FOUS30 KWBC 110851
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
451 AM EDT Sat Jul 11 2026

Day 1 Valid 12Z Sat Jul 11 2026 - 12Z Sun Jul 12 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
ARIZONA AND THE SOUTHERN PLAINS TO THE CENTRAL APPALACHIANS...

...OK into the OH and TN valleys...
An active convective regime is anticipated ahead of a
southeastward moving shortwave trough axis extending from MO to OH.
At 12z this morning, an initial round of convection will be
ongoing from southern IL into portions of KY and TN. Model
guidance supports a transition toward a primarily forward
propagating convective mode this morning, which should place the
overall flash flood risk on a declining trend, though localized
upwind propagation may keep an isolated threat going.

By this afternoon, the primary MCV/shortwave will shift over IL
and IN, interacting with a southward moving frontal boundary to
trigger scattered redevelopment across portions of IL, IN and WV.
Within this zone, PW values near or just under 2" will overlap with
CAPE of 1000-2000 J/kg. While widespread convective organization
is not anticipated, slow cell motions and localized mergers near
the frontal zone will support heavy rainfall rates capable of
producing localized pockets of 2-3" of rain. This is supported by
the 00z HREF and REFS, which both show FFG exceedance
probabilities of 15-40%.

A more organized, and potentially higher end, flash flood threat
is expected to evolve later this afternoon into tonight across
portions of KY and TN. Convection should develop to the south-
southeast of the main shortwave/MCV, likely focusing along remnant
outflow boundaries and instability gradients left behind by the
morning activity. Global deterministic and AI models favor a heavy
rainfall axis focused primarily from KY into northeast TN,
whereas high res models (including the RRFS/REFS) suggest the core
threat may track further south into TN. Given the strong westerly
low level moisture transport south of the MCV, the environment
will be favorable for backbuilding and training convective clusters
tonight. This environment, combined with PWs hovering around 2",
suggests that many HREF members may be underdoing the
afternoon/nocturnal threat. Do expect to see a swath of heavy
rainfall materialize somewhere across the KY/TN corridor, where an
axis of locally higher end flash flood impacts is possible. A
higher end Slight risk is maintained, with a MDT risk upgrade not
out of the question if we gain spatial model convergence and more
confidence on exact convective mode.

Further west, isolated to scattered flash flooding is also expected
across portions of central OK into AR. Low level flow will become
convergent on the southwestern flank of the broader convective
regime. Slow cell motions near a boundary will pose a threat over
OK, while enhanced northerly flow on the western periphery of the
MCV/shortwave will converge with the broad south-southwesterly
inflow to promote some backbuilding/training threat over parts AR.

...Mid-Atlantic...
A localized flash flood threat is forecast across portions of the
Mid-Atlantic. While low level flow will be northerly, one or two
low level convergence axes are projected to setup across the
region, potentially acting as a focus for convection. Despite the
northerly flow, ample moisture and instability will remain in
place. Convective cells will generally track from north to south,
but localized repeating cells will be possible along the trough
axis. The strongest signal for localized 3" totals with the HREF
resides along the coastal plain from NJ southward into southeast
VA where convergence is enhanced. Because FFG values are generally
higher here compared to inland locations, think the overall flash
flood risk should stay isolated, though localized urban and low
lying flood impacts are expected.

...AZ and NM...
The persistent terrain driven pattern continues across the
Southwest, with convection developing over the higher elevations
before propagating southwestward into a pooling instability axis
over the lower deserts of southern AZ. Instability and moisture
profiles should be a bit higher today relative to the past few
days, leading to a corresponding increase in the overall flash
flood risk. Both the 00z HREF and REFS depict greater convective
coverage and higher localized rainfall totals. While fast
southwestward storm propagation and cell speeds may act as a
limiting factor, the moisture/instability footprint should be
sufficient to promote some cell mergers and localized 1-2"/hr
rainfall, justifying the maintenance of the Slight risk.

A Marginal risk has been added to portions of eastern NM. This area
received locally heavy rain yesterday, and the model QPF signal is
a bit stronger today within an environment characterized by
slightly higher moisture and instability. Convection should remain
isolated to scattered, with the primary flash flood threat focused
over recent burn scars, particularly across the Sacramento Mountains.

...TX...
A Marginal risk was added to portions of the TX Hill Country, where
PWs are forecast to climb above 2". Isolated to scattered
convection is expected within a broad southerly low level flow
regime. While most cells will remain transient and produce only
brief downpours, any cells that establish mesoscale organization
could briefly train or backbuild into the low level inflow.
Guidance suggests a weak MCV currently south of the Rio Grande
that may track northward towards the region later today, which
could provide an additional focus for ascent. The risk area aligns
closely with the HREF and REFS 1" EAS probabilities of 10-20%
(signaling organization potential), and 3" neighborhood
probabilities exceeding 40%. Global deterministic and AI suites
also show a distinct convective focus over this corridor.

Chenard


Day 2 Valid 12Z Sun Jul 12 2026 - 12Z Mon Jul 13 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FROM PORTIONS OF
EASTERN KENTUCKY AND TENNESSEE INTO THE CAROLINAS..

...Southeast Quarter of the Country...
A Slight risk has been introduced stretching from KY and TN
eastward into southern VA and the Carolinas. A well defined
shortwave/low over the KY/TN vicinity will interact with a slow
moving backdoor front to focus organized convection. High res
guidance, including the RRFS, FV3 and 3km NAM, indicates a
concentrated axis of convection capable of producing localized
totals exceeding 3". While the global GFS and ECMWF are less
pronounced with their QPF swaths the GEM regional and UKMET are
more in line with the high res guidance. The AIFS and AIGFS also
depict a corridor of enhanced QPF that generally matches the Slight
risk placement. Beneath the closed low over KY and TN, convection
may be less organized, but slow moving. Given PWs near 2" and the
possibility of saturated soils from day 1 rainfall, a flash flood
risk should continue. Across the central and eastern Carolinas PWs
over 2" combined with low level southerly moisture transport and
backdoor frontal convergence should create an environment for high
rainfall rate driven flash flood potential.

Surrounding the Slight risk, a broad Marginal encompasses eastern
NM, TX and much of the Southeast. A southward advancing cold front,
the aforementioned mid level shortwave/low, and upper jet support
will provide the necessary synoptic forcing for scattered
convection. PWs over 2" and CAPE of 2000-3000 J/kg where daytime
heating is maximized, will support heavy rainfall rates. Some
mesoscale uncertainty exists with the track and strength of the
shortwave and frontal positions. An embedded Slight risk or two
may be needed on future updates as confidence increases. Increasing
low level westerly flow along the central Gulf Coast provides a
signature for backbuilding and training, but model divergence on
the exact axis remains. Given the higher regional FFG, did not
want to go with an overly large Slight risk at this time.

...Southwest...
Monsoonal moisture and instability will expand northwestward on
Sunday, necessitating a broader Marginal risk across AZ. While an
embedded Slight risk may eventually be needed, lingering questions
regarding storm coverage and organization keep the risk at
Marginal for now. Current indications suggest that while robust
convection will initiate over the terrain, it will propagate
westward quickly, potentially limiting the threat to isolate
instances of flash flooding.

Chenard
$$
--- MultiMail/DOS
* Origin: capitolcityonline.net * KY, USA (618:250/10)

FOUS30 KWBC 120841
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
441 AM EDT Sun Jul 12 2026

Day 1 Valid 12Z Sun Jul 12 2026 - 12Z Mon Jul 13 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FROM PORTIONS OF
KENTUCKY AND TENNESSEE INTO THE CAROLINAS..

...Southeast Quarter of the Country...
The Slight risk remains in place from portions of KY/TN into
southern VA and the Carolinas. The mid level shortwave feature has
evolved into a deeper closed low, with slow moving convection
expected in the vicinity of that low across portions of KY and TN.
While widespread convective organization is not expected, the slow
storm motions combined with PW values between 1.75" and 2" will
support locally heavy rainfall rates. FFG is lowered across this
region due to antecedent rainfall, making isolated to scattered
exceedance likely today.

Further east from VA into the Carolinas, there is greater
uncertainty regarding convective evolution within a messy mesoscale environment. Large scale forcing ahead of the mid level trough will
interact with a slow moving backdoor front to trigger scattered
convection. Stable air is filtering into southwest VA and central
NC, while easterly flow off the Atlantic is pulling more
instability into eastern VA/NC. Stronger instability exists over
SC south of the front. So overall a messy setup and tough to pin
down where stronger convection may focus long enough for flash flooding.

The primary convective focus will probably be from far southern NC
into SC where the instability is maximized near and south of the
front. A secondary local max could materialize from portions of eastern/southeast VA into eastern NC where easterly flow enhances
convergence. While instability should largely wane tonight
persistent easterly upslope flow into the central and southern
Appalachians overlapping with at least some weak instability could
spark low topped convective development overnight somewhere across
southwest VA or central/western NC.

Overall the broad environmental setup within the Slight risk
remains conducive to heavy rainfall given PWs over 2" and multiple
low level convergence axes. While exact mesoscale boundaries
remain to be pinned down, isolated flash flooding is likely, and a
corridor or two of more concentrate impacts could emerge.

Surrounding the Slight risk, a broad Marginal encompasses eastern
NM, TX and much of the Southeast. A southward advancing cold front,
the aforementioned mid level shortwave/low, and upper jet support
will provide the necessary synoptic forcing for scattered
convection. PWs over 2" and CAPE of 2000-3000 J/kg where daytime
heating is maximized, will support heavy rainfall rates. While
conditions are close to Slight risk thresholds across this
corridor, regional FFG values are higher, and the latest HREF/REFS
EAS probabilities do not highlight a well defined axis of higher
convective concentration. Pockets of over 3" of rain are likely
within this Marginal risk area, but overall coverage is expected
to stay just below Slight risk thresholds.

Consideration was given to a Slight risk upgrade for portions of
north TX today, where a shortwave dropping south into the region
should help focus convection. Localized flash flooding is likely
here, particularly as an urban threat. However due to generally
high FFG and spatial discrepancies with the current model
guidance, we will hold at Marginal.

...Southwest...
Monsoonal moisture and instability will expand northwestward on
Sunday, necessitating a broader Marginal risk across AZ. While an
embedded Slight risk may eventually be needed, lingering questions
regarding storm coverage and organization keep the risk at
Marginal for now. Current indications suggest that while robust
convection will initiate over the terrain, it will propagate
westward quickly, potentially limiting the threat to isolate
instances of flash flooding.

Chenard


Day 2 Valid 12Z Mon Jul 13 2026 - 12Z Tue Jul 14 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
TEXAS INTO THE CENTRAL GULF COAST...

...Texas and Central Gulf Coast...
The Slight risk has been expanded deeper into TX with this update.
Embedded shortwave energy is forecast to migrate westward
underneath a sprawling upper level ridge centered over the Northern
Plains. In the low levels we will see increasing southerly flow
and moisture transport. However, with northerly flow prevailing
aloft, cloud layer mean winds will become weak. Corfidi vectors
will also be oriented north to south, opposite the lower cloud
layer flow...which supports some backbuilding and training threat.
PW values are forecast to exceed 2" over much of central and
eastern TX, with values potentially topping 2.25" over east TX.
Some instances of flash flooding appear likely in this setup.

A favorable synoptic and mesoscale setup for training and
backbuilding is forecast to align along the central Gulf Coast.
Enhanced west to northwesterly low level flow south of the
persistent shortwave/low over the TN/GA vicinity will converge with west-southwesterly inflow off the Gulf. This configuration is
conducive for upwind propagation and some training convection.
Based on latest model guidance, this threat may remain confined
pretty close to the coast. A very moist airmass with PWs around
2.25" will support heavy rainfall rates.

...Southeast and Southern Mid-Atlantic...
A broad Marginal risk remains from TN into the Southeast and
southern Mid-Atlantic. Similar to day 1, a lingering shortwave and
closed low will continue to interact with a a backdoor front. Model
guidance show some spread regarding the exact positioning of these
features and where the primary axis of instability will reside. An
embedded Slight risk upgrade may eventually be needed as these
mesoscale details clarify. At a minimum, localized flash flooding
will occur, but the potential exists for a more concentrated flash
flood threat to materialize. North GA into SC currently appear most
at risk, but will see how todays convection evolves and what the
new high res model show.

...Southwest...
A Marginal risk is maintained from southern NM into AZ, southeast
CA and southern NV. Deep monsoonal moisture will continue to push
northwestward with isolated to scattered convection expected to
result in at least a localized flash food threat.

Chenard
$$
--- MultiMail/DOS
* Origin: capitolcityonline.net * KY, USA (618:250/10)

FOUS30 KWBC 180834
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
434 AM EDT Sat Jul 18 2026

Day 1 Valid 12Z Sat Jul 18 2026 - 12Z Sun Jul 19 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE SOUTHWEST, GREAT BASIN, WEST TEXAS, AND THE NORTHEAST...

...Western Texas to the Four Corners/Great Basin...
Overall, the forecast remains much the same, with mostly minor
spatial adjustments required based on the latest hi-res ensemble guidance.

One of the bigger adjustments was a northward extension
of the Slight Risk across western Texas into the southern
Panhandle. This northern expansion was supported by a slow-moving
upper level shear axis combined with low-level southerly flow,
fueling notable moisture advection into that region. Both the HREF
and REFS guidance have trended more bullish, showing localized
potential for rainfall amounts exceeding 3 inches. These totals
will be capable of producing rapid runoff and localized flash
flooding, especially where soil conditions are more sensitive from
recent rainfall.

Farther west, the Slight Risk remains largely unchanged across
portions of New Mexico, Arizona, southern Utah, and southwestern
Colorado. This remains supported by high-moisture anomalies and
indication from the HREF and REFS for rainfall rates likely to
reach at least 0.5 in/hr in the stronger cells. The Mogollon Rim
looks to remain a focus storm initiation and for some of the higher
storm totals, with both the HREF and REFS showing high
probabilities for accumulations over 2 inches in that area. Recent
heavy rains across this area will likely make it more susceptible
to additional flash flooding.

...Midwest to the Mid Atlantic and Northeast...
A progressive cold front dropping southeastward is expected to
interact with an anomalously moist airmass pooling ahead it. While
the primary Slight Risk remains focused across parts of the
northern Mid Atlantic to southern New England, the broad western
shield of the Marginal Risk was expanded farther west across the
Ohio Valley and into northern Illinois. Within this area, a smaller
Slight Risk area was added over portions western Pennsylvania
where the latest HREF and REFS are indicating localized amounts of
2-3 inches are likely.

For the Slight Risk area over the northern Mid Atlantic and
Northeast, guidance shows two rounds of storms impacting portions
of eastern Pennsylvania, New Jersey eastward to southern New
England. A leading round of storms, well in advance of the front,
is expected to impact the region this afternoon, followed by a second
round accompanying the front itself during the overnight. Many of
the hi-res members suggest the heavier rainfall and potential flash
flooding threat will accompany the initial round, with the loss of
daytime heating and more stable air limiting the threat with the
second. With at least the first round, highly-efficient warm rain
processes and localized cell training may yield quick, short-
duration totals capable of producing isolated to scattered runoff
concerns, particularly in low-lying or urbanized areas. The Slight
Risk largely reflects the higher HREF probabilities for
accumulations of 3 inches or more.

...Florida Panhandle into Southeast Alabama and Southwest Georgia...
Deep moisture spreading north ahead of a slow-moving mid-to-upper
level low will pool along a surface trough extending out of the
eastern Gulf. This moisture (PWs increasing to around 2 inches)
will fuel slow-moving storms developing by the late afternoon that
will be capable of producing heavy rates, which along with their
slow movement, may produce heavy amounts and isolated flash
flooding.

Pereira


Day 2 Valid 12Z Sun Jul 19 2026 - 12Z Mon Jul 20 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS THE
SOUTHWESTERN U.S. FROM WEST TEXAS TO SOUTHERN UTAH...

...Southwestern U.S....
The overall synoptic configuration remains largely unchanged from
the previous period, with a persistent monsoon pattern locked in
place -- keeping scattered to widespread convection in the forecast
from West Texas into the Great Basin and southern Rockies. Given
that PW anomalies remain notably high at 2-3 std dev above normal,
and soil conditions moist from prior rainfall, confidence was
sufficient to introduce a Slight Risk that extends from West Texas northeastward across southern New Mexico, central and northern
Arizona, into southern Utah.

An upper-level high centered over northern Utah and Colorado will
support steady easterly flow across the southern tier, effectively
tapping into and beginning to pull mid-level energy that has been
centered over West Texas along this deeper moisture axis. The
highest areal average precipitation amounts are expected to center
along the higher terrain, where slow-moving storms are expected to
develop with afternoon heating, before propagating off of the
terrain along convective outflows. Given sensitive, moist soil
conditions from successive days of widespread storms, much of this
area remains vulnerable to rapid runoff. Complex terrain, slot
canyons, and recent wildfire burn scars will further accentuate the
threat for flash flooding across parts of the region.

...Mid Mississippi Valley east to the Carolinas and south to the
Eastern Gulf Coast...
A more expansive Marginal Risk has been drawn for this period,
reflecting deep moisture atmospheric profiles and an increasing
potential for localized heavy rainfall amounts producing isolated
runoff concerns. This risk is centered along a cold front dropping
into North Carolina and the Tennessee Valley, while is begins to
slow over the lower Ohio and mid Mississippi valleys. Diurnal
heating and prefrontal convergence will tap into this moisture
pool, generating clusters of slow-moving efficient thunderstorms,
capable of producing 1-2 inch totals, with isolated higher amounts.
There remains a greater threat for more widespread heavier amounts
along the eastern extent of this area, centered over southeastern
Virginia and eastern North Carolina, where more defined upper
forcing will help accentuate the threat for amounts over 3 inches.

Additionally, the Marginal Risk has been extended southward down to
the Gulf Coast. This accounts for the deep tropical moisture
arriving ahead of the slow-moving disturbance lingering in the
eastern Gulf, as well as favorable low-level convergence focusing
along a slow-moving surface trough extending north from the Gulf.
Highly efficient warm-rain processes along these features will
maintain a threat for heavy, short-term duration totals and
isolated runoff concerns.

Pereira
$$
--- MultiMail/DOS
* Origin: capitolcityonline.net * KY, USA (618:250/10)

FOUS30 KWBC 190921
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
521 AM EDT Sun Jul 19 2026

Day 1 Valid 12Z Sun Jul 19 2026 - 12Z Mon Jul 20 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE SOUTHWESTERN U.S. FROM WEST TEXAS TO SOUTHERN UTAH, AS WELL AS
EASTERN NORTH CAROLINA AND THE VIRGINIA TIDEWATER REGION...

...Southwestern U.S....
Overall, the synoptic pattern remains much the same, with the
monsoon ridge remaining favorably aligned. PW anomalies of 2-3 std
dev above normal will remain across much of the highlighted area.
This moisture, along with sufficient instability, and areas of
enhanced ascent afforded by easterly-drifting mid-level energy.
will support another day of widespread convective activity. Slow-
storm motions along with likely cell-mergers will raise the threat
for locally heavy amounts and flash flooding concerns. Flash
flooding remains a distinct threat in slot canyons, dry washes,
burn scars, and low desert areas via mountain outflows. The Slight
Risk highlights the area where HREF and REFS guidance indicate the
threat for 1-2 inch amounts is greatest. The REFS, and to a lesser
extend the HREF, indicate that heavier totals of 3+ inches are
possible over portions of West Texas along the Mogollon Rim down
into southeastern Arizona.

...Lower Missouri Valley to Southeastern Virginia and Eastern North Carolina... A targeted Slight Risk remains centered over eastern North
Carolina and extends into southeastern Virginia. Convection will
develop ahead of a slow-moving cold front that will be dropping
into a very moist (PWs 2+ inches) and unstable (MUCAPE > 2000
J/kg) environment, while some modest right-entrance region upper
jet forcing will offer some enhanced ascent. Heavy totals appear
likely, with both the HREF and REFS showing high neighborhood
probabilities for amounts over 3 inches within the Slight Risk area.

Less organized activity is expected back along the front extending
across the southern Appalachians, Tennessee Valley, and parts of
the lower Ohio, mid Mississippi, and lower Missouri valleys. While
widespread heavy totals are not expected, the moisture-rich
environment (PWs 1.75-2 inches) is expected to support storms
capable of producing localized heavy amounts and isolated runoff concerns.

...Eastern Dakotas into the upper Mississippi Valley...
A shortwave moving off of the top of the western U.S. ridge will
interact with a frontal system advancing through the northern
Plains into the Upper Midwest. An amplifying west-southwesterly
low level jet will support increasing PWs (1.75-2 inches) and
instability east of a warm front. The overnight guidance differed
greatly on the details but continued to present some signal for
backbuilding and training storms, capable of producing locally
heavy rates within the area highlighted by the Marginal Risk.

...Eastern Gulf Coast into the Southeast...
An area of low pressure located over the northeastern Gulf is
gradually becoming better defined, with additional development
becoming more likely. The footprint for heavy amounts through early
Monday is expected to remain mostly offshore, although some
heavier amounts along the immediate Florida Gulf Coast cannot be
ruled out. Therefore, the Marginal Risk was maintained.

An axis of enhanced low level convergence and pooling moisture to
the north is still expected be a focus for diurnal storms capable
of producing heavy rates. Therefore, a Marginal Risk was maintained
from the central Gulf Coast northward into the Tennessee Valley.
HREF and REFS indicate localized totals exceeding 2 inches are
likely along this corridor.

Pereira


Day 2 Valid 12Z Mon Jul 20 2026 - 12Z Tue Jul 21 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF
WEST TEXAS, NEW MEXICO, AND ARIZONA...

...Southwest and Great Basin...
Mid-level energy moving west of the region, and dry air advection
from the south will begin to diminish the heavy rainfall and flash
flooding threat over West Texas. However farther west, the
monsoonal moisture plume will remain firmly in place, ensuring
another day of high-efficient rainfall production over portions of
the Southwest and Great Basin.

Models show the upper high originally centered over Utah and
Colorado beginning to slide southeast, allowing moisture and
energy to spread northwest into the Great Basin and along the
western slopes of the Sierra Nevada -- raising the potential for
increasing storm activity and isolated runoff concerns in those area.

The greater heavy rainfall and flash flooding threat will remain
focused from southwestern New Mexico and southeastern Arizona
northwestward along the Mogollon Rim into northwestern Arizona.
This is expected to be the focus for better synoptic forcing and
greater instability -- supporting intense short-duration rain rates
that will elevate the risk for flash flooding, especially in areas
of complex terrain, dry washes, and burn scars.

...Upper Great Lakes...
An amplifying upper trough supported by energy diving out of
Canada will advance from the upper Mississippi Valley to the upper
Great Lakes. Strong southwesterly to west-southwesterly low level
inflow will continue to sustain deep moisture ahead of the cold
front and across the advancing warm front. This moisture along with
strong forcing, produced in part by left-exit region upper jet
dynamics, will generate organized convection capable of producing
rainfall rates of 1-2 in/hr. Fast storm motions should limit the
overall heavy accumulation and flash flooding threat. However,
localized short-term training could raise at least some isolated concerns.

...North Carolina and Southern Virginia...
Maintained a Marginal Risk across this area. Apart from the GFS and
REFS, the general model consensus indicates that activity will be
less organized. However, a lingering boundary and corresponding
pool of deep moisture (PWs 2+ inches) will support additional
storms capable of producing heavy downpours. Should the guidance
begin to trend more toward the GFS and REFS, a targeted upgrade
may required, especially if more models begin to show back-to-back
days of overlapping heavy amounts.

...Gulf Coast...
The models continue to show the footprint of the heaviest amounts
associated with the disturbance over the northern Gulf remaining
mostly offshore. Therefore maintained only a Marginal Risk along
the coast from West Florida to southeastern Louisiana. Moisture
pooling along an axis of enhanced low level convergence northwest
of the circulation may extend the threat for heavy rainfall further
inland into the far lower Mississippi Valley.

Pereira
$$
--- MultiMail/DOS
* Origin: capitolcityonline.net * KY, USA (618:250/10)

FOUS30 KWBC 200827
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
427 AM EDT Mon Jul 20 2026

Day 1 Valid 12Z Mon Jul 20 2026 - 12Z Tue Jul 21 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL FOR PORTIONS OF THE
SOUTHWEST AS WELL AS FOR EASTERN NORTH CAROLINA...

...Southwest...

Very few changes were needed with the inherited Slight Risk area
from far west Texas, southwestern New Mexico, and much of Arizona
with this update. Monsoonal moisture will stream north off the Gulf
of California and into the Four Corners region today. With peak
heating, afternoon thunderstorms are expected over much of the
Slight Risk area. Much of the area has seen afternoon thunderstorms
causing localized flash flooding in recent days, and the same
pattern continues today. The threat further east will be driven by
a subtle shortwave disturbance retrograding west along the Mexican
border. This will allow for greater longitudinal spread of storms
to include far west Texas. MUCAPE values will be between 1,000 and
2,000 J/kg across much of the region, as PWATs rise above 1.5
inches in some areas. Between the aforementioned disturbance and
local topography, expect widely scattered instances of flash
flooding where the storms today are most persistent.

...Eastern North Carolina...

A stalled out front along the VA/NC border at the start of the day
will retreat northward in the form of a warm front as deep tropical
moisture advects northeastward from the tropical depression in the
Gulf. The front will provide enough forcing across much of eastern
North Carolina to allow for a renewed round of widespread showers
and thunderstorms in the area. Soils remain generally dry over most
of the area, despite storms impacting some of eastern North
Carolina yesterday. Due to the well above normal amounts of
moisture for the storms to work with, as well as the front
providing some forcing, the Slight Risk was expanded west to
overlap some of the areas of North Carolina that are being impacted
by storms currently, generally just east of Charlotte. Otherwise,
the threat remains similar to yesterday, so few changes were needed
with this update.

...Gulf Coast...

The outermost northern and western periphery of Tropical Depression
Two continues to impact much of the Gulf Coast of Florida, through
the Panhandle, and over to southeastern Louisiana. The storms are
few and far between, but ample moisture associated with a
developing tropical cyclone is allowing for any storms to have the
potential to produce multiple inch per hour rates. Regardless, the
center remains far enough offshore, with drier air aloft working to significantly cut down on the overall coverage of storms.
Considering the dry soils and high FFGs typical of the immediate
Gulf Coast, even periods of heavy rain should only result in
isolated instances of flash flooding. Thus, the inherited Marginal
remains in place.

...Midwest...

The Marginal Risk across much of the Midwest and upper Great Lakes
also remains largely the same today. There remains considerable
uncertainty as to coverage of storms impacting the area today into
tonight. It appears the most likely areas to be impacted stretches
from the southeastern corner of Minnesota south through eastern
Iowa and into northeastern Missouri. However, even in this area,
dry soils and the height of the growing season should allow most of
the rain expected to water the crops in the region, with minimal
threat for flash flooding. Thus, few changes were needed with this update.

Wegman


Day 2 Valid 12Z Tue Jul 21 2026 - 12Z Wed Jul 22 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
ARIZONA AND UTAH, AS WELL AS THE UPPER OHIO VALLEY AND INTO THE
MID-ATLANTIC...

...Arizona into Utah...

Increasing monsoonal moisture, particularly into southern Arizona
will combine with an approaching upper level shortwave trough to
further increase convective converage across portions of the
Southwest on Tuesday as compared with previous days. The
introduction of a northwestward-moving shortwave trough will allow
the convective activity to wane over eastern New Mexico and west
Texas, and instead promote more activity into eastern Nevada, Utah,
and portions of Colorado and Wyoming. Numerous highly flash-flood
prone slot canyons, dry washes, and rocky soils will allow the many
storms that form over the region to cause scattered instances of
flash flooding. The Slight Risk area was expanded north to include
much of Utah and into eastern Nevada for this region. The greatest
convective coverage and most impactful flash flooding is expected
over portions of Arizona and the boot heel of New Mexico. A
higher-end Slight remains in effect along the Mogollon Rim, but has
been expanded to the Mexico border along the AZ/NM border with this update.

...Upper Ohio Valley through the Mid-Atlantic...

A strong cold front pushing south across the Midwest will run into
plentiful tropical moisture being drawn north from Tropical
Depression 2 in the Gulf. The front will act as a catalyst for
numerous segments of mostly fast moving thunderstorms across the
Mid-Atlantic and Ohio Valley on Tuesday. With PWATs ahead of the
front over 2.25 inches in some instances, and in most areas above 2
inches, the storms will have plentiful juice to work with, allowing
for heavy rainfall to impact most areas from the central and
northern Appalachians to the urban I-95 corridor from Richmond up
through Boston. The fast moving nature of the storms should mean
most areas have severe concerns as higher priority than flash
flooding. However, it's likely that backbuilding and training
storms on the book ends of any segments could cause widely
scattered instances of flash flooding. Thus, the Slight Risk
inherited over much of the Mid-Atlantic remains in place with few changes.

...Gulf Coast...

Tropical Depression 2 is expected to gradually drift west, with the
center following near the Gulf Coast. All of the guidance suggests
that northerly shear and dry air entrainment will push any
meaningful associated heavy rainfall south of the center over the
Gulf, leaving very little rainfall to impact the immediate Gulf
Coast. Thus, despite being a tropical cyclone with local PWATs up
to 2.5 inches, the distinctive lack of rainfall for most land
areas, especially away from the immediate coast remains an unusual
feature with TD2. The Marginal Risk in place over most of the
northern Gulf Coast from the Florida Panhandle west through
southeast Louisiana remains in place with few changes.

Wegman
$$
--- MultiMail/DOS
* Origin: capitolcityonline.net * KY, USA (618:250/10)

FOUS30 KWBC 210847
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
447 AM EDT Tue Jul 21 2026

Day 1 Valid 12Z Tue Jul 21 2026 - 12Z Wed Jul 22 2026

...THERE ARE SLIGHT RISKS OF EXCESSIVE RAINFALL FOR PORTIONS OF THE
SOUTHWEST AND GREAT BASIN AS WELL AS FOR PORTIONS OF THE OHIO AND
TENNESSEE VALLEYS AND INTO THE NORTHEAST...

...Southwest and Great Basin...

The combination of anomalous monsoonal moisture streaming northward
out of the tropical Pacific and a retrograding upper level
shortwave will create a very active day for thunderstorm activity
this afternoon across much of the Pacific Northwest. Moisture
amounts will be anywhere from 2-4 sigma above normal, with PWATs
above 1.5 inches in southern Arizona, and above 1 inch across much
of the rest of the Southwest. The upper level disturbance tracking
west out of New Mexico will force numerous thunderstorms to form
across Arizona. The storms will slowly track westward. Greater
concentrations of storms are expected along the Mogollon Rim where
topography will help allow the storms to congeal along the Rim. Due
to the above normal amounts of moisture, the storms will be capable
of heavy rainfall with the strongest cores possibly producing
rainfall rates to 2 inches per hour. Given the very favorable
hydrology of the Desert Southwest for flash flooding, given
generally very hydrophobic soils and bare rocks, the Slight Risk
remains in place across much of Arizona, with a higher-end Slight
stretching from the southeast corner of the state northwestward
along the Rim to the Grand Canyon. As usual, slot canyons, dry
washes, and other low-lying areas will be more susceptible to
impactful flash flooding downstream of the heaviest rains.

Further north across the Great Basin, the area will be on the
western periphery of the large ridge over Colorado and a nearly
stationary longwave trough off the coast of northern California. A
separate shortwave trough will track across Nevada and into Idaho
this afternoon. Given similarly anomalous amounts of atmospheric
moisture in place as well across this largely flash-flood prone
area from the Sierras east through Utah, clusters of storms will
form in this area associated with the upper level shortwave.

The inherited Slight was expanded west to include the Sierras,
where upslope will greatly contribute to afternoon and evening
thunderstorm activity there, while the steep slopes will support
fast-forming flash flooding downstream of any heavy rain producing thunderstorms. Elsewhere, few changes were needed, as many of the
areas in the Slight that will be impacted by storms again today
were impacted on previous days, worsening the flash flooding risk.

...Ohio and Tennessee Valleys into the Northeast...

Much of the flooding risk across the eastern half of the country
today will be in association with a strong cold front at the
leading edge of a strong longwave trough over the Great Lakes
pushing south and east across the Ohio and Tennessee Valleys as
well as into the Northeast. Anomalous moisture originating in part
from T.S. Bertha in the Gulf will ride northeastward ahead of the
front, providing plentiful moisture for numerous thunderstorms to
form, some of which will produce multiple-inch-per-hour rainfall
rates. A few areas within the broader Slight Risk are likely to
see more rainfall. In central Kentucky and central Tennessee, a southwest-to-northeast oriented band of storms is expected to form
on the leading edge of the cold front, with mesoscale "slow-downs"
in the front's progression allowing for a second round of activity
possibly forming over these same areas where FFGs are depressed
from heavy rainfall in recent days.

The greatest rainfall totals are expected to be across portions of
southeastern Virginia, generally from the Richmond metro east
across the Bay and impacting the lower Maryland and Virginia
sections of the Delmarva. Here, a plume of greater moisture will
interact with the front which will be slowed by its passage across
the mountains. An early to mid afternoon round of storms with the
initial approach of the upper level trough and associated shortwave
energy will move across southern Virginia first. Much more numerous
storms will impact the area in the evening hours as the main front
approaches the area. Despite the loss of daytime heating, the front
is expected to stall over southern Virginia, which could very well
allow for a prolonged period of training storms to set up in the
aforementioned area, which will persist through the overnight. A
short-fused Moderate Risk cannot be ruled out should this evolution
play out as expected by several of the CAMs.

Finally, across the area form northern New Jersey northeast into
the Hudson Valley, morning thunderstorms caught along the Catskills
and Poconos associated with a warm front may start out the day with
a period of training thunderstorms as moisture and instability
levels increase south of the front. This will likely be the feature
that causes the most rainfall in the area. Once the fast-moving
cold front sweeps eastward across the area, resulting in a much
shorter period of widespread thunderstorm activity, its passage
will end the threat for heavy rain in this area for the night.

...Gulf Coast/Tropical Storm Bertha...

As has been the case for several days, the convective pattern with
Bertha in the guidance is little changed. Northeasterly shear will
continue to keep any persistent heavy rainfall well south of the
Gulf Coast for the next several days. Only small and isolated bands
of rain trying to wrap around the center will impact the coast.
The inherited Marginal Risk remains little changed from Louisiana
through the Florida Panhandle.

Wegman


Day 2 Valid 12Z Wed Jul 22 2026 - 12Z Thu Jul 23 2026

...THERE ARE SLIGHT RISKS FOR EXCESSIVE RAINFALL OVER PORTIONS OF
THE INTERMOUNTAIN WEST AS WELL AS FROM NORTHERN GEORGIA THROUGH THE
TIDEWATER OF VIRGINIA AND NORTH CAROLINA...

...Intermountain West...

Highly anomalous amounts of atmospheric moisture associated with
the monsoon over the Intermountain West will be activated by rapid
height falls as an upper level and highly negatively tilted trough
pushes east from off the coast of Washington and Oregon. Meanwhile,
separate upper level energy undercutting the ridge will also
provide additional forcing further east across eastern Idaho and
Wyoming. Once again, numerous thunderstorms will form in the
anomalous moisture and for many areas, will be tied to the local
topography. Few changes were needed with this update. The greatest
amounts of rain look to concentrate in western Wyoming, where any
storms south of Yellowstone could necessitate a higher-end Slight
for some of those areas, as well as for the Uintas of northern
Utah. With nearly all of the forcing further north, the Marginal
Risk into southern Arizona and southern New Mexico was trimmed
significantly with this update, as ridging quickly overtakes this
area and limits convective potential south/west of the Mogollon Rim
as a result.

...Carolinas, Southern Virginia, and Northern Georgia...

A strong cold front running into highly anomalous moisture being
siphoned from the circulation of Tropical Storm Bertha will
exacerbate the gradient of moisture along the frontal interface
through the day across the Carolinas and into southeastern
Virginia. This will work to keep any forward progress of the front
minimal. Storms will train along the front, especially across
northeastern North Carolina and into southeastern Virginia. This
area remains in a higher-end Slight Risk and with the stalled out
front remaining to guide the frequent development of additional
storms, a Moderate Risk upgrade in areas where the storms focused
in the Day 1 period remains a distinct possibility. Guidance has
been laser focused in this area and so forecast changes have been
minimal. Further south and west, however, guidance has become
increasingly optimistic on storms developing further west into the
southern Appalachians. As such, the Slight Risk was expanded west
to include this region from north of Atlanta through the western Carolinas.

...Tropical Storm Bertha/Gulf Coast...

Strengthening shear across the circulation will continue to keep
any organized convection and meaningful rainfall out over the open
waters of the Gulf. The immediate coastline could still see amounts
greater than an inch, but the rainfall footprint continues to shift
off the coast. In coordination with LIX/Slidell, LA forecast
office, the inherited Slight Risk for this region was downgraded
with this update, with the overall area of the surrounding Marginal
remaining little changed. What little rainfall does impact land
areas remains with the potential to be locally heavy, so
unfortunately no changes to the Marginal Risks can be made so long
as Bertha remains a tropical entity.

Wegman
$$
--- MultiMail/DOS
* Origin: capitolcityonline.net * KY, USA (618:250/10)

FOUS30 KWBC 220826
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
426 AM EDT Wed Jul 22 2026

Day 1 Valid 12Z Wed Jul 22 2026 - 12Z Thu Jul 23 2026

...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FOR SOUTHEASTERN
VIRGINIA AND EXTREME NORTHEASTERN NORTH CAROLINA...

...Southeast...

A strong but painfully slow moving cold front draped across
Virginia today will continue to act as a train track along which
numerous showers and thunderstorms will move throughout the day and
into tonight. It's probable that many areas from western North
Carolina through Raleigh and into the Hampton Roads area of
southeast Virginia will see more time over the next 24 hours seeing
moderate to heavy rainfall than dry time. The heaviest and most
persistent rainfall will be into extreme northeastern North
Carolina and much of southeastern Virginia southeast of Richmond
today. The Hampton Roads metro appears to be the most at risk of
the metro areas expected to be impacted by heavy rains today. It's
likely areal averages in the Hampton Roads area will exceed 3
inches today through tonight. Given both the persistence of the
heavy rain and urban concerns, the inherited Moderate Risk area
will remain unchanged with this update, generally following the
state line east from I-95 to the mouth of the Chesapeake.

Elsewhere the Slight Risk area extending from northern Georgia to
the Delmarva was shrunk both on the north and south sides with this
update. The CAMs guidance are in good agreement on the corridor
where heavy rain and flash flooding will be, increasing the
confidence that a smaller latitudinal range will be covered by the
heavy rain. As such, the southeastern corner of NC and all but
northern SC were removed from the risk categories as the heaviest
rains will stay north of those areas for today. They'll get their
turn in the coming days. The length of the front will promote heavy
rain development towards the west, and as such the Slight was
expanded west into northeastern Alabama with this update, where the
combination of the front and topography will both support areas of
heavy rain and widely scattered instances of flash flooding.

...Intermountain West...

The Slight Risk area covering an expansive area of the
Intermountain West from southwestern Montana south through
northwestern New Mexico was largely unchanged with this update.
However, in coordination with ABQ/Albuquerque, NM forecast office,
the Slight Risk area was expanded south along the AZ/NM state line
with this update. Plentiful burn scars, relatively little amounts
of rain it's taken in some areas to cause flash flooding, and many
areas not seeing recent flooding at all are all contributing
factors to the Slight Risk upgrade. Meanwhile further north, the
heaviest rainfall totals will be tied to the topography in many
areas from the Bitterroots through Yellowstone, much of Utah and
western Colorado. With sufficient upper level forcing helping the
storms to form and cause flash flooding, it's probable in many
instances that any storms that start along the topography will move
off the mountains towards the northeast, so lower elevation valleys
in between also remain in the Slight Risk for flooding.

...Gulf Coast/Tropical Storm Bertha...

T.S. Bertha will continue to struggle from strong northeasterly
shear pulling nearly all of the significant associated rainfall
south over the open waters of the Gulf. With little rain expected
along the Gulf Coast, the inherited Marginal remains little
changed. The Marginal mostly covers the fact that any significant
tropical cyclone carries inordinate amounts of atmospheric
moisture, even when being sheared. That moisture can easily support
heavy rainfall, even if isolated, so the Marginal threat remains.

Wegman


Day 2 Valid 12Z Thu Jul 23 2026 - 12Z Fri Jul 24 2026

...THERE'S A MODERATE RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
EASTERN NORTH CAROLINA...

...Southeast...

A strong and very slow moving cold front draped across portions of
the Mid-Atlantic on Wednesday makes only very slow progress through
the day Thursday across far southern Virginia and northwestern
North Carolina. A second day of intense rainfall in the form of
seemingly endless trains of storms will impact much of the
Carolinas on Thursday. The good news is the southward progress of
the front on the order of about 50 miles or so will spare most of
Virginia much heavy rainfall for yet another day. However, this
means the heavy rain simply impacts areas further south across much
of North Carolina and northern South Carolina. Unfortunately there
looks to be some overlap in the heavy rainfall footprints from
Wednesday into Thursday, particularly in northeastern North
Carolina, likely extending from Norfolk south and east. Once again
the heaviest rainfall amounts will likely concentrate along the
coast. As such the Moderate Risk for this period was also
unchanged, focused from I-95 east and from I-40 north and east.

Further west, a similar situation remains as on Wednesday.
Painfully slow southward movement means many of the same areas get
hit with heavy rains again on Thursday as on Wednesday. The Slight
Risk was expanded west along the front due to the large amounts of
atmospheric moisture in place immediately ahead of the front. Many
areas have PWATs above 2 inches. The Slight Risk area includes
metros Birmingham, AL, Atlanta, and into Charlotte, NC. All 3 of
these metros have some risk of training storms, with Charlotte the
highest of those 3.

...Central Plains...

A pair of nocturnal MCSs, one Wednesday night into Thursday
morning, and a second much stronger one Thursday night into Friday,
will impact portions of southeastern Nebraska, northeastern Kansas,
and into small portions of Iowa and Missouri through the period.
These back-to-back MCSs will sufficiently soak the soils such that
the heavy rain with Thursday Night's MCS will cause widely
scattered instances of flash flooding, especially where urban areas
such as Lincoln, Topeka, St. Joseph, and possibly Omaha and Kansas
City are impacted. The area of the Slight was adjusted, but remains
little changed with this update. The isolated flash flooding threat
represented by the Marginal extends well west of there through
nearly all of Wyoming and Colorado. While the flooding threat
diminishes considerably in these states compared with Wednesday,
the leftover saturated soils and still likely formation of showers
and storms will keep an isolated flash flooding threat going.

...Bertha/South Texas...

Latest CAMs guidance are starting to come into agreement on a
solution that keeps the circulation of Bertha intact over the
northwestern Gulf before the westward moving storm moves inland in
Texas near or south of Houston. As such, the persistent convection
that continues to focus south/southwest of the center eventually
impacts land areas, in this case in south Texas. A Marginal Risk
covering much of South Texas was introduced with this update. It's
likely that a Slight Risk upgrade will be needed with future
updates, short of a northward jog in the guidance that kills off
the rain much earlier, as the guidance had been showing in recent
days. The area most likely to see that upgrade is around Corpus
Christi through Victoria.

Wegman
$$
--- MultiMail/DOS
* Origin: capitolcityonline.net * KY, USA (618:250/10)

FOUS30 KWBC 281352
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
952 AM EDT Tue Jul 28 2026

Day 1 Valid 1345Z Tue Jul 28 2026 - 12Z Wed Jul 29 2026

...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FOR PARTS OF
EASTERN PENNSYLVANIA, NEW JERSEY, SOUTHERN NEW YORK, AND FAR
WESTERN CONNECTICUT...

...Southern Appalachians through New England...
1345Z SPECIAL UPDATE: A special update was coordinated with WFO Mt.
Holly and the National Water Center to extend the Moderate Risk
southward through the remainder of eastern Pennsylvania, as well as
the I-95 corridor through Philadelphia and Wilmington, DE.
Increasing hi-res model signal for intense rain rates, particularly
between 18Z and 03Z, prompted the upgrade. The combination of
moderate to strong instability and PW values increasing through the
day to between 1.6 and 1.9 inches will make rain rates reaching 2
inches per hour in the strongest convection likely, and there is a
chance the most organized clusters could see rain rates reach 3
inches per hour. In an area with a lot of flashy streams and
urbanization, this will make flash flooding increasingly likely
this afternoon, potentially impacting the evening rush in parts of the area.

PREVIOUS DISCUSSION: An anomalously strong upper low will produce
impressive dynamics to create the potential for significant flash
flooding across the Tri-State area today and tonight.

A closed low will be forming over Upstate NY this evening and then
continue to amplify and deepen as it curls southeast into New
England. This intense system will help drive increasing divergence
downstream, which when combined with the accompanying height falls
will result in broad deep layer ascent from the Mid- Atlantic into
New England. At the same time, the deepening system will force
acceleration of the 850mb inflow,

Precipitable water values and the magnitude of the surface-based
CAPE will be near climatological maximums (reflected via the SPC
sounding climatology), with precipitable water values around 1.75
inches overlapping most-unstable CAPE of 2000-3000 J/kg. Strong
ascent in the vicinity of this anomalous closed low and near the
accompanying occluded surface low into these strong thermodynamics
sets a situation favorable for heavy, training rainfall, and flash flooding.

The 28/00Z HREF and REFS both maintain probabilities for 2"/hr
rainfall reach 15-25%, and Corfidi vectors aligned anti- parallel
to the mean wind which will be aligned to the approaching front,
which suggests a strong backbuilding and training potential. This
fostered enough confidence for the day-shift to upgrade part of the
area to a Moderate Risk. The Moderate risk was maintained with the
western boundary of the Slight and Moderate expanded a bit
westward--mainly in New York state--due to the model suite slowing
down the timing of convective initiation and propagation.

...Four Corners States across the Central Plains...
The expansive monsoon ridge will become additionally squeezed as
shortwaves rotate anti-cyclonically around it both to the north and
south. This will again support at least scattered monsoon
convection as precipitable water values at or above 1 inch northward
into the Four Corners overlapped with sufficient instability for
afternoon development. Once again the risk will likely initiate in
the higher terrain during the onset of peak heating, and then there
appears to be sufficient shear (20-30 kts) for some organization
off the terrain and into the lower elevations, primarily in New
Mexico and Colorado, although there is potential for storms to be
very slow movers.

...Western Florida Peninsula and the Keys...
A shortwave diving along the Florida Peninsula/Western Gulf will
interact with broad diffluence aloft to maintain deep layer ascent
for convection across the eastern Gulf and into parts of South
Florida and the keys. Mean 0-6km winds of just 5-10 kts will be
aligned SW to NW, anti- parallel to collapsed Corfidi vectors, and
parallel to the Keys. This suggests that convection will repeatedly
build across the Gulf where PWs will be pooled at 2-2.25 inches
within impressive 2000-3000 J/kg MUCAPE leading to 2-4" of
rainfall with locally higher amounts.

...Missouri Valley...
Overnight convection leading into the start of the Day 1 period at
29/12Z prompted a Slight Risk area ahead of the storms. The
expectation is that the storms will weaken...followed by the next
round of storms later today into tonight as a weakening shortwave
crests the monsoon ridge before diving southeast. As the shortwave
moves along a front tonight...it will help accelerate the already
intensifying LLJ to draw robust thermodynamics northward. This will
support organizing clusters of convection or an MCS aligning to
the front as both 0-6km mean winds and Corfidi vectors become
parallel. With rainfall rates likely reaching 1-2"/hr at times, any
training has the potential to produce 2-4" of rain (HREF and REFS
probabilities for 3+" 20-25%) leading to instances of flash flooding.

Bann/Weiss


Day 2 Valid 12Z Wed Jul 29 2026 - 12Z Thu Jul 30 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
THE NORTHEAST...

...Northeast...
Rainfall rates and additional rainfall amounts will initially be
heavy early in the period over the eastern portion of the Northeast
before they begin to diminish on Wednesday as an anomalously deep
low pressure system begins to occlude. There should be rainfall
rates around one inch per hour leading to widespread 1-3" of rain
with locally higher amounts.

The latest guidance still depicts a sharp gradient of instability
which may limit the rates in parts of Vermont, New Hampshire and
Maine. This part of the Northeast US should have received less
rainfall with Flash Flood Guidance less likely to have been
compromised. The previous outlook largely had this covered and
changes were fairly minor with this outlook.

...Four Corners States into the Central/Northern Plains...
Monsoonal flow persists with isolated to widely scattered
convection extending from the Four Corners region north and
eastward...perhaps extending as far east as the plains of Colorado.
Some of this rain could fall atop soils saturated from heavy rain
on Tuesday and Tuesday night. It remains possible that a Slight
Risk area may be needed for parts of the High Plains but there was
not enough confidence to do so in this outlook.

...Central Gulf Coast Region into parts of the Southeast...
A cold front stalling along the Gulf Coast will be a focus for slow
moving and training thunderstorms on Wednesday. Guidance continues
to indicate a low-probability threat for at least 3" of rain due to
training of 1-2"/hr rain rates within favorable thermodynamics.
This region can generally tolerate significant rain rates and this
amount of rainfall, but any more pronounced training could result
in isolated flash flood related impacts.

Bann/Weiss
$$
--- MultiMail/DOS
* Origin: capitolcityonline.net * KY, USA (618:250/10)

FOUS30 KWBC 291137
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
737 AM EDT Wed Jul 29 2026

Day 1 Valid 12Z Wed Jul 29 2026 - 12Z Thu Jul 30 2026

...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
THE NORTHEAST...

11z Update: We expanded the MDT risk westward into eastern NY given observational and model trends. A stationary convergence axis is
focusing a band of intense rainfall over far eastern NY...a bit
west of earlier forecasts. Not much instability along this axis,
but strong convergence is overcoming this and supporting low
topped convection with efficient warm rain processes. As the low
over Long Island moves northward expect the rainfall axis to pivot
and persist over eastern NY, and portions of far western CT/MA.
Areas of significant flash flooding are likely through the
morning, with high end life-threatneing impacts possible across the
mid to upper Hudson Valley and point just east towards the CT/MA border.

Chenard

...Previous Discussion...

...Northeast...
Intense rainfall will be on-going over portions of the Northeast as
the Day 1 period begins at 29/12Z, with some training of cells and
some places experiencing multiple rounds of heavy rainfall--particularly
across western Massachusetts, far southern Vermont, and broadly
across southern New England. Rainfall rates between 1-2"/hr at
times will be possible through late morning/early afternoon and
totals of 2-4" (with localized higher amounts possible) are expected.

HREF/RRFS neighborhood probabilities from the 29/00Z runs remained
high (greater than 80 percent) for 3" totals across
western/central MA into far southern VT. Probabilities are moderate
(30-50 percent) for 5" totals.

Given the setup and risk of significant flash flooding continuing
from the day 1 period, a Moderate Risk was maintained with few
changes given the cumulative rainfall amounts. After 30/00Z...the
intensity of rainfall should subside while also shifting eastward.

...Four Corners States into the Central/Northern Plains...
Monsoonal flow persists with isolated to widely scattered
convection extending from the Four Corners region northward and eastward...perhaps extending as far east as the plains of Colorado.
Some of this rain could fall atop soils saturated from heavy rain
prior to the start of the Day 1 period at 29/12Z. Persistence in
the pattern and moisture distribution leaves the risk area in good
shape with the Slight Risk focused on eastern Colorado.

...Central Gulf Coast Region into parts of the Southeast...
A cold front stalling along the Gulf Coast will be a focus for slow
moving and training thunderstorms today into tonight. Guidance
continues to indicate a low-probability threat for at least 3" of
rain due to training of 1-2"/hr rain rates within favorable
thermodynamics. This region can generally tolerate significant rain
rates and this amount of rainfall, but any more pronounced
training could result in isolated flash flood related impacts.

Taylor/Bann


Day 2 Valid 12Z Thu Jul 30 2026 - 12Z Fri Jul 31 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE LOWER MISSOURI AND MID TO UPPER MISSISSIPPI VALLEY...

...Lower Missouri Valley into the Mid-Upper Mississippi Valley...
Shortwave energy will be progressing east southeast as it tracks
across parts of the central and northern plains on Thursday into
Thursday night/early Friday morning. The shortwave energy will be
encountering an increasingly moist and unstable airmass with
precipitable water values in excess of 2 inches being drawn into
the region ahead of the shortwave. Given the MCS/upscale growth
potential with this system, concentrated areas of heavy rain are
expected given the potential for training and repeat-convection. The
Slight Risk remained in good shape and only minor adjustments were
needed to covers the 29/00Z ensemble guidance and to account for
the uncertainty/spread among the models.

...Four Corners States into the Central/Northern Plains...
Monsoonal flow and anomalous deep-layer moisture will maintain an
isolated excessive rainfall risk extending from eastern Arizona
northeastward across much of western and northern New Mexico into
parts of Colorado. The expanding mid/upper level ridge will likely
limit the coverage compared to recent days.

...Central Gulf Coast Region into parts of the Southeast...
Heavy rainfall is expected along a front associated with a low
pressure system which will be pulling away from New England.
Heavy rainfall with some potential of flooding will be focused
along and near the front...especially over parts of Florida and
Georgia near the state line.

...New England...
The departing low pressure is expected to be across eastern MA at
the start of the period and transition off the coast during the
period. Locally heavy rainfall will remain possible across the
region given its proximity and ample moisture to work with. While
the instability will likely be less compared to Tuesday/Wednesday,
the stronger dynamics at play and potential for training rainfall
could lead to a localized threat, particularly if over areas more
saturated from previous rainfall. A Marginal Risk was maintained.

Taylor/Bann
$$
--- MultiMail/DOS
* Origin: capitolcityonline.net * KY, USA (618:250/10)

FOUS30 KWBC 020829
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
429 AM EDT Sun Aug 2 2026

Day 1 Valid 01Z Sun Aug 02 2026 - 12Z Sun Aug 02 2026

..THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR THE FLORIDA BIG
BEND REGION, COASTAL NORTH CAROLINA AND THE EASTERN GREAT LAKES
INTO THE NORTHEAST AND NORTHERN/CENTRAL APPALACHIANS...

...East Coast States...

Widespread showers and thunderstorms are expected from the Gulf
Coast of Florida through the Mid-Atlantic States, and into the
interior Northeast. A highly amplified trough will be tracking
though the region. A strong upper level jet will help provide
impressive synoptic ascent from the Gulf Coast all the way into New
England. Meanwhile Gulf moisture will be drawn northward ahead of
the system with PW values climbing into the 2-2.25 inches range.
Widespread thunderstorm are expected to break out and capable to
produce rain rates of 1-2 inches/hour with the potential for
repeating/training of cells. A broad Marginal Risk are spans from
the eastern Gulf Coast up the Eastern Seaboard to th Northeast and
Ohio Valley.

There are three areas with a more focused threat. The first is
across the Florida Gulf Coast/Big Bend and just inland where heavy
rain will occur over recently saturated soils. An additional 3-5
inches of rain is possible (30-50% chance of at least 5 inches)
due to backbuilding of cells across the Gulf repeating onshore with
2-3 inches/hour rates. Within this region, an enhanced slight risk
was added for Taylor, Dixie, and Lafayette counties which is where
the 2-day rainfall is expected to be heaviest.

Another area of locally higher excessive rainfall risk exists along
the eastern Great Lakes from around Cleveland, Ohio through
Buffalo, New York and into the Northern Adirondacks and southward
for the Central Appalachians where there is a Slight Risk for
excessive rainfall. While instability may be a bit less here, this
is also the region where a pivoting deformation axis and
accompanying mid- level TROWAL may exist north of the closed low.
This will produce some higher thermodynamics into which storms,
which will be slow moving and training, can repeat with 1-2
inches/hour rain rates.

And the third area is for coastal North Carolina where there is a
signal for 2-5 inches of rainfall too fall over recently saturated
soils. A Slight Risk area was raised for this part of the state.

..Southwest...

During this time the ridge will be expanding eastward however the
convective activity is expected to stay suppressed across Arizona,
New Mexico and West Texas. The challenge Sunday is that it appears
there will be some drying that occurs from NE to SW as a decaying
front drops across Texas, followed by a weak surface trough as
well. This suggests that during peak heating, there will actually
be somewhat of a deterioration of the environment, further limiting
convective coverage. Any storms that do develop will have the
potential to yield local hourly rates of 1 inch/hour that lead to
isolated instances of flash flooding.

Campbell/Weiss


Day 2 Valid 12Z Sun Aug 02 2026 - 12Z Mon Aug 03 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR THE TRI-STATE
AREA OF NEW YORK, NEW JERSEY, AND CONNECTICUT, COASTAL CAROLINAS
AND BIG BEND OF FLORIDA...

...East Coast...

The impressive upper trough/low moving across the Ohio Valley is
progged to cutoff once again as it digs into the Southeast by
Tuesday morning. Downstream of this anomalous feature, robust PWs
of more than +2 sigma will flood the Atlantic Seaboard, combining
with a ribbon of elevated instability within the deep layer WAA to
produce an environment supportive of heavy rainfall for nearly the
entire coast. While specific locations for heavier rainfall and a
greater excessive rainfall risk are difficult to discern at this
time range, it appears nearly any location that received repeating
showers and thunderstorms with 1-2 inches/hour rain rates could
experienced impacts. The Marginal Risk area stretching from Florida
to Maine was maintained.

The narrow Slight risk for the Tri-State area of CT/NJ/NY and
northwest Rhode Island was maintained due to extremely vulnerable
soils from recent heavy rainfall in this area. A small Slight
Risk area was raised for the Big Bend of Florida where additional
heavy rain may pivot onshore Monday after 2-days of heavy rain this
weekend. A Slight Risk was also raised for coastal areas of South
and North Carolina given additional rainfall is expected to fall
over very saturated soils.

...Southwest...

The ridge will continue to expand farther east while weak
vorticity impulses rotate around it. Moisture and instability will
gradually lift northward during this time, allowing for an
expansion north of an environment supportive of heavy rain. The
limiting factor Monday appears to be instability. The Marginal Risk
area was maintained for isolated instances of excessive rainfall
leading to flash flood related impacts are expected for parts of
Arizona, New Mexico and far western Texas.

...Northern Plains...

A shortwave will quickly track along the International border
bringing height falls to the Dakotas and Minnesota. Southwest flow
will direct Gulf moisture and instability northward to help support
the development of heavy rainfall. Storm motion is expected to be
quite progressive however there may be briefs periods where training/backbuilding occurs. As rainfall rates climb to 1+
inches/hour, any training could create locally excessive rainfall.

Campbell/Weiss
$$
--- MultiMail/DOS
* Origin: capitolcityonline.net * KY, USA (618:250/10)

FOUS30 KWBC 120822
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
422 AM EDT Wed Aug 12 2026

Day 1 Valid 12Z Wed Aug 12 2026 - 12Z Thu Aug 13 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE
CENTRAL PLAINS THROUGH THE TENNESSEE VALLEY, AND FOR THE DESERT SOUTHWEST..

...Central Plains southeast to the Tennessee Valley...
Extremely active convective weather continues Wednesday as a "ring
of fire" type setup continues with mid-level waves rotating atop a
ridge to bring convective clusters to the region.

The ridge responsible for this setup amplifies across the Southern
Plains but does retreat subtly in the east resulting in pinched
flow around its northern periphery. Within this flow, multiple
shortwaves will lift out of the Four Corners and then race E/SE
from the Central Plains through the Ohio Valley in a pattern very
repetitive from previous days. While the exact placement of any of
these shortwaves is difficult to determine even on D1, each ripple
interacting with a stationary front draped across the region will
result in clusters of thunderstorms moving repeatedly across the
region, with ascent additionally enhanced by a jet streak
positioned near the Canada/U.S. border leaving its diffluent RRQ
overtop this area. While storms will generally track NW to SE
within the region of greatest thickness gradient, small variations
in mesoscale features can play a significant role in where the
heaviest rainfall will occur.

This activity will develop within robust thermodynamics as a plume
of elevated PWs reaching +1.5 to +2 sigma arcs around the ridge and
pools along the front, collocated with impressive MUCAPE driven by
an EML noted in regional forecast soundings lifting out of Mexico
and around the ridge. Although lapse rates weaken farther east into
the Ohio Valley than the Central Plains, this results in deeper
column saturation to support intense rainfall rates, for which the
HREF neighborhood probabilities suggest will exceed 2"/hr at times.
The most intense rain rates will occur within any MCS development
as 0-6km bulk shear of 40-60 kts drives strong convective
organization, which with mean 0-6km winds aligned to both the front
and the Corfidi vectors, indicates a strong likelihood for periods
of training. While there continues to be uncertainty as to the
exact footprint of the heaviest rainfall, anywhere prolonged
training of these intense rain rates can occur, more than 5 inches
of rain is possible.

As noted above, confidence in the exact placement of the heaviest
rainfall remains uncertain due to model variations in the placement
of these, already notoriously difficult to forecast, mid-level
impulses. However, both the REFS and HREF depict a region of higher probabilities from Iowa through Kentucky, with a subtle SW trend
noted in the accompanying deterministic guidance. Some of this rain
will fall atop recently saturated soils from prior heavy rain, but
in general the axis of heaviest rain may just miss those areas. For
this reason changes to the inherited ERO were modest and cosmetic.

...Southwest/Great Basin/Four Corners...
The subtle eastward retreat of the expansive mid-level ridge over
the southern tier of the CONUS in response to a trough diving along
the Pacific Coast will allow for more intense moisture and
thermodynamic return into the region today. This evolution will not
only allow for elevated PWs to stream northward (widespread +2 to
+2.5 sigma and above the 97th percentile according to NAEFS), but
will also weaken the cap as mid-level temps fall to enhance
available instability. Additionally, forcing for ascent will be
maximized as multiple weak impulses lift northward from Mexico
around the ridge periphery, acting upon the favorable
thermodynamics to drive widespread convective development.

Coverage of thunderstorms today should be quite widespread,
potentially one of the more active days of the entire monsoon
season so far. Simulated reflectivity from the high-res CAMs
suggest storms will develop as far west as the Sierra, while
covering as well most of the Four Corners, Great Basin, and into
the High Plains. Mean 0-6km winds of 10-15 kts will allow for at
least some more progressive movement than previous days, but bulk
shear of 20-30 kts and persistent southerly moist inflow will help
to organize convection resulting in periods of possible
training/backbuilding. With rain rates likely reaching 1"/hr at
times, this could produce locally 3" of rain, but even where total
rainfall is less, the intensity of the rain could still cause flash
flood related impacts. The greatest threat will be across
vulnerable features like burn scars, dry washes, canyons, and urban
areas, but activity is expected to be widespread today, especially
where any morning cloud cover does not limit instability later
today. After coordination with the affected WFOs, a SLGT risk was
expanded to include most of Arizona, the slot canyon region of
Utah, and far southern Nevada.

Weiss


Day 2 Valid 12Z Thu Aug 13 2026 - 12Z Fri Aug 14 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
THE MIDWEST THROUGH THE OHIO VALLEY, THE CENTRAL AND NORTHERN HIGH
PLAINS, PORTIONS OF THE SOUTHWEST, AND THE EASTERN SIERRA/WESTERN
GREAT BASIN...

...Midwest/Ohio Valley...
The active pattern from Wednesday continues almost without respite
into Thursday. A wavering stationary front positioned north of an
impressive mid-level ridge (500mb heights climbing above the 90th
percentile over the Gulf Coast/Southeast) will again be the focus
for waves of thunderstorms. As is the case on D1, and even moreso
on D2, ripples of energy moving within the pinched westerlies and
atop this boundary will help focus ascent for thunderstorm
development, and the upstream connection to the Mexican EML and
Pacific moisture will provide favorable thermodynamics for intense
rainfall. In fact, PWs on Thursday may be higher than any other day
this period, with a plume of 2.25" PWs progged to align near the
front, reflected in the NAEFS with an area exceeding the 99th
percentile of the CFSR climatology. This is focused in a stripe
from central IA through southwest OH, which is also where the ECMWF
EFI reaching 0.7/SoT of 1-2.

This is a more cohesive signature among the models for focused
heavy rainfall, although the greatest risk area may occur on the
upstream portion of this region as reflected by REFS indicating a
high risk (>60% chance) for at least 1"/hr rates, with the
environment supporting the training of 2"/hr rates at times also.
This is also where the AI (both GFS and ECMWF) focus the heaviest
rainfall and is also where the greatest REFS/GEFS/ECENS
probabilities for 3+" of rainfall exist. Conceptually this could be
the region of greatest training as convection develops over NE/IA
and backbuilds along the boundary before organizing into
clusters/MCS and moving more progressively eastward. While anywhere
across this region could experience flash flooding, especially
since the vulnerability will be increased due to antecedent
rainfall, the inherited SLGT (and enhanced SLGT) was expanded to
the west with this update.

...Four Corners through the Northern High Plains...
Widespread convection is again expected in a broad area from the
Four Corners into the Northern High Plains as moisture streams
around a ridge centered over the Gulf Coast. This re-centering of
the mid-level ridge will continue the evolution which begins on
Wednesday of allowing more open 700-500mb flow out of Mexico and
the Pacific to support elevated PW anomalies across a broad region
of the Western CONUS. This is reflected by NAEFS PW anomalies
above the 90th percentile covering most of the this region, with a
focused area of anomalies above the 99th percentile spreading into
the Northern High Plains.

Within this impressive thermodynamic plume, forcing for ascent
will intensify thanks to broad height falls as a trough digs in
from the Pacific, with several mid-level impulses rotating up
through the flow to locally enhance deep layer lift. At the same
time, a stationary front will be draped from Montana through the
Central High Plains, with additional ascent provided via upslope
mechanisms in its wake, especially within the High Plains. As bulk
shear increases to 35-45 kts, the setup will become increasingly
supportive for clusters of thunderstorms containing rain rates
above 1"/hr traversing generally SW to NE (W to E farther north),
and repeating through multiple rounds. The REFS/SREF/GEFS all
indicate regions of 3+" of rain occurring, with the general focus
matching the locations of highest EFI, which also concurs with the
inherited ERO and first guess fields. For these reasons, changes to
the inherited risk areas were modest and cosmetic due to overall
consistency for these areas.

...Southwest/Great Basin...
Broadening upper level trough moving along the Pacific Coast will
bring expanding height falls to the Southwest, with pinched flow
between this trough and a ridge over the Gulf Coast/Southeast
driving pronounced thermodynamic advection northward. PWs will
again exceed 1 inch all the way into Utah (+1 to +2 sigma), but
this will be actually slightly less anomalous than what is
anticipated to exist on Wednesday /D1/. Still, with these elevated
PWs overlapping MLCAPE of 500-1000 J/kg, another active day of
convection is anticipated, with locally elevated bulk shear of
20-25 kts helping to organize development, especially near the
AZ/NM border. Mean winds will be generally light at 5-10 kts across
AZ/NM and from the south, but any organization could locally result
in some training/merging to enhance rainfall. This would be most
problematic over any urban areas, dry washes, canyons, and burn
scars, and the inherited SLGT risk was only modified cosmetically
for new guidance.

However, a second SLGT risk area was added for portions of the
Great Basin/western Nevada where the overlap of high PWs and
significant CAPE will support multiple rounds of thunderstorms.
Both the HREF and REFS guidance indicate an elevated risk of flash
flood guidance exceedance over this area, so after coordination a
targeted SLGT risk was added here as well.

Weiss
$$
--- MultiMail/DOS
* Origin: capitolcityonline.net * KY, USA (618:250/10)

FOUS30 KWBC 130904
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
504 AM EDT Thu Aug 13 2026

Day 1 Valid 12Z Thu Aug 13 2026 - 12Z Fri Aug 14 2026

...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL CENTERED OVER
CENTRAL TO SOUTHERN INDIANA...

...Iowa to Kentucky...
A broad higher end Slight risk (25%) area extends from portions of
IA into KY on the periphery of the strong upper ridge centered
over the South. An MCS will likely be ongoing across portions of
IA at 12z this morning, moving off to the east into IL by
afternoon. Most indications are that this system will be forward
propagating by this time, which should limit the coverage and
magnitude of the flash flood threat to some extent. With that
said, high rainfall rates are expected (2-3" an hour possible),
and scattered flash flooding is likely. Another round of convection
is likely later tonight as low level moisture transport increases
into the stalled front. This setup has training/backbuilding
potential, and a more significant flash flood threat could evolve.
It is this second round of convection that could push this to a MDT
risk across portions of IA and IL...however there is a bit more
uncertainty with the exact magnitude and axis of this overnight
activity. The MCS rolling though this morning should play some role
in the boundary position and strength by tonight. Thus we will
hold just shy of a MDT risk and let day shift evaluate
observational trends and the 12z HREF.

The corridor across IN and KY that got hit hard by flash flooding
yesterday will need to be closely monitored again today and
tonight. The MCS moving across IA/IL should be approaching eastern
IN and northern KY by late this afternoon or evening. Most
indications are that the MCS will be in a weakened state by that
time as it outruns the better forcing and low level flow. However
with an axis of instability likely present, would expect some
convection to persist, and certainly a possibility the MCS
maintains intensity more than currently forecast. Hopefully any
activity that is there will be moving at a decent clip...but at
least localized flash flooding is likely given the saturated
conditions. Then attention turns to tonight into early Friday...as
the training convective axis mentioned earlier over IA/IL should
also extend into portions of IN/OH/KY. Again some uncertainty with
the exact axis and magnitude, but areas of heavy rainfall are likely.

There is high confidence that areas of at least locally heavy
rainfall will be in the vicinity of the corridor hit with major
flash flooding yesterday. Lower confidence that high end rainfall
amounts intersect the corridor of most saturated conditions...but
there is some chance that this does indeed occur. So overall, there
is high confidence in additional lower end impacts, and low to
medium confidence in more significant considerable to locally
catastrophic impacts. Thus we went ahead and upgraded this corridor
to a Moderate risk with this update.

...High Plains...
A favorable pattern for scattered to widespread showers and
thunderstorms from CO into MT today into tonight. PWs will be
around mid August max values across this corridor, so heavy
rainfall rates are likely. One area of increased convective
coverage is expected across portions of northeast CO into
northwest KS. This is highlighted by HREF FFG exceedance
probabilities around 25% and the HREF PMM QPF getting upwards of
150-200% of FFG. Convection developing over the terrain should move
eastward into the low level inflow, likely helping produce some
cell training and mergers. Given the aforementioned PWs and over
1000 j/kg of CAPE, some flash flooding appears likely.

A second relative max in QPF is forecast over northeast MT where
850mb moisture transport and convergence is maximized. Less CAPE
this far north, and so rainfall rates are not forecast as high.
Thus not surprising that we see less in the way of FFG exceedance
in the HREF. Nonetheless, the pattern is persistent, which does
support some training of activity, and should be at least some
instability to drive higher rainfall rates. So still would expect
some flash flooding issues to develop...just maybe more localized
in nature than further south where the instability is greater.

...Southwest...
A broad Slight risk stretches from AZ into NV today. The core of
strongest forcing and highest moisture shifts a bit northwest
compared to Wednesday. Thus HREF/REFS FFG exceedance probabilities
are a bit less over AZ, but higher over portions of NV and UT. So
while isolated to scattered flash flooding is likely over the
entire Slight risk area, the greater coverage of convection should
be over NV and UT.

Chenard


Day 2 Valid 12Z Fri Aug 14 2026 - 12Z Sat Aug 15 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR THE FRONT RANGE
AND HIGH PLAINS OF COLORADO AND WESTERN NEBRASKA, PORTIONS OF THE
UPPER MIDWEST AND OHIO VALLEY, AND PORTIONS OF THE SOUTHWEST...

...Iowa to West Virginia...
A corridor of convection will continue to be favored near a
stalled front on the periphery of the strong upper ridge centered
over the southern U.S.. There are some larger latitudinal
differences by this time time in the models, however, the AIFS and
AIGFS have been pretty consistent with a farther south axis, and
this aligns well with the 00z 3km NAM and RRFS. Thus we leaned in
this direction with the Slight risk corridor given the good track
record of the AI guidance, and the agreement with the available CAMs.

The strongest forcing and moisture convergence should end up
along the western end of this Slight risk area...and PWs over this
region should be even higher than what we have on day 1. While some
models have this axis farther north into WI...our current
preference keeps it across IA into IL. This may very well overlap
areas that see heavy rainfall and flash flooding on day 1. Thus we
will consider this area a higher end Slight risk, and there is the
potential for a MDT risk upgrade on future updates pending model
trends and how convection on day 1 evolves. Significant flash
flooding is certainly a possibility in this setup over portions of
IA into IL, especially if/where there is overlap from day 1
rainfall. The QPF signal is a bit less pronounced farther
southeast into IN/OH/WV...but the environment will be conducive
for heavy rainfall rates and periodic training here as well. Thus
given wet antecedent conditions stretching across this corridor the
Slight risk was expanded to the southeast.

...High Plains...
A Slight risk remains for portions of northeast CO into southwest
NE. A similar setup as Thursday, with high PWs and CAPE supporting
heavy rainfall rates. Also some model spread here...but a solid
model clustering between the AIFS/AIGFS/RRFS/Gem reg supports the
Slight risk area as having the greatest convective coverage Friday.

...Southwest...
A Slight risk was added to portions of northwest AZ, southeast NV
and southwest UT. PWs will probably be a bit lower by this time,
but still expecting sufficient CAPE, and stronger forcing given
the approaching mid level trough. The HREF members and RRFS depict
good convective coverage, and FFG exceedance probabilities similar
to day 1 (Thursday)

Chenard
$$
--- MultiMail/DOS
* Origin: capitolcityonline.net * KY, USA (618:250/10)

FOUS30 KWBC 150836
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
436 AM EDT Sat Aug 15 2026

Day 1 Valid 12Z Sat Aug 15 2026 - 12Z Sun Aug 16 2026

...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FOR PARTS OF THE
OHIO VALLEY...

...Ohio Valley...
A Moderate risk has been expanded to stretch from portions of
eastern IL through IN and across much of OH. An MCS is forecast to
be ongoing at 12z this morning tracking across IL and IN. While
this complex should generally exhibit a weakening trend as the
morning progresses, it will be traversing a corridor of saturated
ground conditions. Consequently, scattered to numerous instances of
flash flooding remain expected into the morning hours.

Another threat will materialize by this evening into the overnight
hours, driven by the remnant MCV from the morning convection. This
feature will help focus additional convective development over OH,
eventually spreading east southeastward into WV and far southwest
PA by late tonight and early Sunday. A very moist airmass
characterized by PWs around 2.3" will support intense hourly
rainfall rates. A training and backbuilding signature again
exists, with deep layer westerly flow and strong low level
westerly moisture transport resulting in weak Corfidi vectors.
HREF neighborhood FFG exceedance probabilities range from 50-80%,
with HREF PMM QPF exceeding FFG thresholds by 200-300% in spots
and overall FFG exceedance spatial coverage topping 50%. These
impressive metrics support numerous instances of flash flooding
tonight over central and southern OH, with the threat spreading
into WV and southwest PA by early Sunday. Some of this flash
flooding will likely be considerable in nature.

...High Plains...
A Slight risk is maintained from eastern CO into central and
western KS, reflecting a southward shift relative to continuity.
The overall setup remains similar to recent days, with convective
forcing along the periphery of the upper ridge interacting with a
moist, unstable airmass.

A cold front will serve as a primary convective focus, with
activity developing north of the boundary where the better
moisture/instability will be pooling. Convection initiating over
the higher terrain will track eastward and may grow upscale
along/north of the front as it moves from CO into KS, aided by
upper level jet right entrance dynamics. Isolated to scattered
flash flooding is expected, particularly across eastern CO where
recent heavy rainfall has lowered FFG thresholds.

...Southeast...
A broad Marginal risk continues across the Southeast on the
periphery of the strong upper ridge centered over the southern
U.S. Anomalous moisture with PWs approaching the the percentile
for mid August will be present, and HREF neighborhood probabilities
support localized 3" rainfall totals However, overall convective
coverage is expected to remain low with a minimal HREF EAS signal.
While sea breeze boundaries may provide localized focus, any flash
flooding impacts should remain isolated.

Chenard


Day 2 Valid 12Z Sun Aug 16 2026 - 12Z Mon Aug 17 2026

...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
WEST VIRGINIA...

...OH Valley into the Mid-Atlantic...
A Moderate risk upgrade has been issued for portions of WV.
Persistent and strong westerly 850mb moisture transport impinging
into the complex terrain is concerning, favoring convective
training and/or repeat activity. This setup, combined with PW
values forecast to exceed 2", supports the potential for numerous
instances of flash flooding. An initial round of convection should
be ongoing at 12z Sunday with an active training/backbuilding
threat. While a relative lull in coverage may occur after this,
activity is expected to ramp back up by afternoon into the evening
along and ahead of an approaching cold front. While this latter
activity may lean more progressive the high PW airmass could
easily yield a quick 1-3" of additional rainfall. Given that soil
conditions will likely be quite saturated by this time,
considerable flash flooding impacts are a distinct possibility in
and near the terrain of WV. While some uncertainty with the details
exist, the 00z Gem reg, RRFS, REFS hit this area with over 3" of rain.

A Slight risk extends eastward across PA, MD, NJ, DE and northern
VA. A mid level shortwave/MCV, alongside the synoptic cold front,
will provide ample forcing for convection across the region. PWs
increasing towards 2.3" and strong low level moisture transport
will create an environment conducive to heavy rainfall rates. An
MCS approaching from the west at 12z Sunday may tend to weaken as
it outruns the primary instability axis, but additional convective
initiation is expected in its wake as instability and moisture
increase ahead of the front. While the cold front will eventually
push the convection along, the environment ahead of the front will
be favorable for backbuilding/training with weak Corfidi vectors.
Any training will pose a flash flood risk, particularly over
sensitive urban corridors. The Slight risk was adjusted southward
to align with guidance trends, with the 00z RRFS and REFS matching
well with the AIGFS/AIFS axis.

The Slight risk was also expanded westward into the OH Valley to
account for additional convection over saturated soil conditions.
Additional convection is expected along/ahead of the advancing
cold front within an airmass characterized by CAPE exceeding 3000
J/kg and PWs near or just over 2". While individual cells should
move more quickly compared to previous days, the saturated
conditions mean even progressive heavy rates will produce scattered
flash flood impacts.

...Southwest...
A Slight risk continues from northeast NM into southeast CO,
focused along and north of a cold front where low level convergence
and easterly upslope flow are maximized beneath upper level right
entrance jet dynamics.

While PW values are not extremely high, they remain slightly above
average, and ample instability will compensate to support isolated
to scattered flash flooding from slow moving cells and cell
mergers. Guidance from the AIGFS, RRFS, and REFS is in good
agreement with this spatial placement.

Chenard
$$
--- MultiMail/DOS
* Origin: capitolcityonline.net * KY, USA (618:250/10)

FOUS30 KWBC 160833
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
433 AM EDT Sun Aug 16 2026

Day 1 Valid 12Z Sun Aug 16 2026 - 12Z Mon Aug 17 2026

...THERE IS A MODERATE RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF
WEST VIRGINIA...

...OH Valley into the Mid-Atlantic...
A complex, multi wave convective scenario will unfold across the
OH valley and Mid-Atlantic today, with a Moderate risk in the ERO
centered over WV, surrounded by a Slight risk extending eastward
into PA, MD and VA, and a Marginal risk extending westward across
the OH Valley into MO.

At 08z, one MCV accompanied by locally training convection was
tracking eastward over southeast OH into WV and southwest PA. This
feature will traverse PA, MD and northern VA through the morning
and early afternoon hours. As this area of convection outruns the
better instability pool, overall convective intensity should
gradually lessen...however an anomalously moist airmass with PW
values around 2.25" will still support heavy rainfall rates within
embedded cores. Although higher FFG east of the Appalachians and
weaker instability to the northeast should limit widespread
exceedance, a sharp instability gradient setting up along the southern/southwestern flank (from northern VA into MD) could
support some backbuilding by late morning into the afternoon.
Given the high PW environment, any training or backbuilding will
pose a flash flood threat, especially across urban areas.

Behind this initial wave, thermodynamic recovery will occur as a
secondary MCV shifts into OH closer to an advancing cold front.
Additional convective development is expected over OH, WV and
western PA...supported by CAPE near 2000 J/kg and PWs approaching
2.2". While the cold front will eventually push the activity
southeastward, strong low level westerly moisture transport
aligned with the deep layer flow will be supportive of backbuilding
and training.

A Moderate risk remains centered over WV, where persistent, strong
850mb moisture transport impinging into the complex terrain raises
significant hydrologic concern. Multiple rounds of convection are probable...the initial morning round primarily impacting the
northern portion of the state, followed by another round of
convection dropping south across the state between 00z and 06z.
There are some notable differences between the 00z HREF and
REFS...with the REFS showing higher QPF and FFG exceedance
probabilities. Given the moist upslope flow, high PW values, and
robust instability, favor something closer to the wetter
guidance...although some uncertainty still exists regarding the
exact convective evolution and FFG exceedance coverage
today/tonight. Scattered to numerous instances of flash flooding
are possible...with considerable flash flood impacts a possibility.

The Slight risk extending into PA/MD/VA accounts for the potential
of multiple rounds of rain, backbuilding, and localized
convergence near a west to east instability gradient that may help
focus convection. Although the 00z HREF and REFS explicit FFG
exceedance probabilities are muted (probably a reflection of high
FFG and QPF spread over multiple rounds), the high PW airmass will
promote high rainfall rates capable of producing areas of flash
flooding. Also FFG may lower through the day as rounds of rain
move across, and thus think the low model FFG exceedance
probabilities may be a bit misleading. While widespread flash
flooding is not currently expected, would expect this setup to
result in an isolated to scattered threat, and locally considerable
impacts are a possibility.

Further west, a Marginal risk covers the remainder of the OH
Valley into MO, where scattered convection along the southward
dropping cold front will bring an isolated flash flood threat to
areas with saturated soils and lowered FFG.

...Southwest...
A Slight risk is maintained from northeast NM into southeast CO,
with the 00z high res models supporting minimal changes from continuity. Convection will focus near and north of a front, where enhanced
low level convergence and easterly upslope flow will combine with
upper level right entrance jet support. While PW values are only
slightly above average, ample CAPE of 1000-2000 J/kg will
compensate, driving isolated to scattered flash flooding from slow
moving storms and cell mergers.

Chenard


Day 2 Valid 12Z Mon Aug 17 2026 - 12Z Tue Aug 18 2026

...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS
OF THE OHIO AND TENNESSEE VALLEY AND APPALACHIANS, THE SOUTHWEST
AND UPPER MIDWEST ...

...OH/TN valley into the Appalachians...
A southward dropping cold front will serve as a focus for scattered
convection on Monday. While overall storm coverage will be reduced
compared to previous days, lingering moisture and instability just
behind the boundary will maintain a heavy rainfall threat from KY
and TN into the central Appalachians, enhanced by local terrain
upslope. A Marginal risk is maintained for isolated flash
flooding. Notably, the 00z RRFS and REFS hint at an upstream MCV
moving into KY and TN that could increase convective
coverage/organization enough to warrant a Slight risk. However,
given limited global model support, the risk tier will be held at
Marginal pending a full suite of high res guidance in subsequent cycles.

...Southwest...
A Marginal risk remains on track across much of NM and adjacent
portions of southeast AZ and southern CO. Beneath an upper level
ridge strong instability and slightly above average PWs will
interact with embedded shortwave energy trapped in the weak flow.
Terrain based initiation is expected during the afternoon, with
scattered coverage and cell mergers likely as convection drifts off
the higher elevations.

...NE to MN...
The Marginal risk has been adjusted slightly southwestward, now
extending from central NE into far southeast SD and far northwest
IA. Frontal forcing combined with a robust instability pool over
the Central Plains and a nocturnal low level jet ramp up will
support a convective cluster centered across NE by Monday
evening/night. Recent high res models, along with the AIFS and
AIGFS, show better spatial agreement focusing this activity over
NE, supporting the minor shift in the risk area.

Chenard
$$
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FOUS30 KWBC 180759
QPFERD

Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
359 AM EDT Tue Aug 18 2026

Day 1 Valid 12Z Tue Aug 18 2026 - 12Z Wed Aug 19 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE MIDWEST AND MISSOURI VALLEY...

...Midwest to Missouri Valley...

Current WV satellite imagery depicts the arrival of our first
shortwave migrating southeast around the broad trough to the north
and over the northern fringes of the ridge dominating the Southern
CONUS. Pathway of least resistance will maintain a consistent
approach of northwest to southeast trajectory of the next series of
shortwaves wandering through the mean flow between the two key
upper features over the next 72 hrs. The first disturbance will be
the precursor to a more potent shortwave ejecting out of the
Northern Rockies the second half of the period. Anticipating the
current shortwave analyzed over the Wyoming Front Range through the
Sandhills to propagate east-southeast with the main energy pivoting
through the Corn Belt and Upper Mississippi Valley before kicking
east towards the southern portion of the Great Lakes by later this
evening and continuing its progression eastward. This disturbance
will be the headline feature for areas of the Midwest between
MN/WI/IL with the latest CAMs maintaining some variability in how
they want to handle the convective scheme during the afternoon and
evening period today. Current prospects are generally 50/50 on
whether or not we see any significant thunderstorm genesis across
the aforementioned area as relevant positive vorticity advection
and the introduction of a cold front should manifest at least some
scattered convective activity across the Upper Midwest towards the
western Great Lake areas spanning I-94/41 between Chicago and Milwaukee.

Deterministic outputs around the Great Lakes maintain at least
some moderate totals with a few more aggressive CAMs noting more
substantial rainfall prospects as the setup yields a better
organized convective cluster, thus tipping the scales to a more
enhanced rainfall prospect by the late-afternoon and early evening
time frame prior to the arrival of the cold front from the
northwest. Latest 00z HREF neighborhood probs for >2" is hovering
between 20-35% across northeastern IL into southern WI with the
primary focus lying between I-94 and I-80 in the above region.
Considering the antecedent soil moisture anomalies remaining
elevated, especially the top layer soils which have taken a beating
the past week from incessant convective complexes and the like, as
well as elevated stream flows lingering from said impacts, the
prospect for localized flash flooding is a bit higher than normal.
As such, with a signal still present in some of the CAMs and the
local Chicago WFO messaging the threat for locally enhanced flood
concerns with the disturbance, there was no reason to deviate from
the previous SLGT risk in place as the environmental conditions and
synoptic pattern do favorable the potential for later today before
the cold front finally ushers in some much needed drier air in its wake.

Further to the west and southwest, the threat is a bit less
variable in its presentation within the latest CAMs suite as the
second, more prolific shortwave to eject out of the Northern
Rockies is all but certain to provide to a more enhanced convective
episode across areas of eastern NE down through the quad-state area
of NE/MO/KS/IA as the shortwave amplifies and digs southeast out of
the Sandhills. Fairly textbook setup of regional diffluence ahead
of the trough as it migrates through the High Plains into the
Missouri River Valley, entering an environment that will yield much
more favorable low to mid-level shear and elevated PWAT anomalies
as flow becomes backed for a time with the troughs approach.
Convective initiation across NE will ensue late this afternoon,
carrying through the evening as the mean flow will take any
activity and press it southeast with sights on northeastern KS and
northern MO as we move into the evening. From there, a modest
nocturnal LLJ will nose up through KS allowing for a localized
convergence signature and a narrow corridor of low-level shear
enhancement to maintain better mesocyclone structures that will
wander southeast through northeast KS into MO. Heavy rainfall will
maintain a southeastward heading with a pretty solid consensus of
1-2", locally higher amounts of rainfall extending from the KS/NE
border down through central MO. This is highlighted by modest >2"
probs off the latest HREF with the axis aligned perfectly with the
expected frontal positioning by the end of the forecast. These are
the more likely locations to see flash flooding given the more
favorable forcing, moisture presence, and potential for repeating
leading to a maintenance of the SLGT risk from the previous forecast(s).

Kleebauer

...Eastern Florida Peninsula...

Broad trough expanding across the east will dig slightly into the
Southeast Tuesday, pushing a cold front and pre-frontal trough
towards the Gulf Coast. This pre-frontal trough is progged to push
down the Florida Peninsula in response to a push of a modest
shortwave impulse embedded within the flow. As this
trough/shortwave dive southward, the overlapping ascent will merge
with the pinned sea breeze into robust thermodynamics characterized
by PWs of 2-2.25 inches and MUCAPE above 3000 J/kg. This will
support scattered to widespread thunderstorm development, with
rainfall rates eclipsing 2"/hr. While this setup is favorable for
locally enhanced rainfall and totals between 3-5" in the hardest
hit locations, antecedent soil moisture remains low and probs for
FFG exceedance maintain a meager signal as FFG's remain upwards of
3.5-4"/hr across all of northeastern FL into the FL Panhandle.
Considering the nature of the precip being scattered in nature and
the signals within the latest CAMs a little less robust than the
previous forecast, decided to remove the previous MRGL risk, but
maintain a posture for a non-zero flash flood threat with the
greatest potential likely between Jacksonville to Daytona Beach.

Kleebauer/Weiss


Day 2 Valid 12Z Wed Aug 19 2026 - 12Z Thu Aug 20 2026

...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF
THE MID-MISSISSIPPI AND OHIO VALLEYS...

...Mid-Mississippi and Ohio Valley...

Amplifying shortwave trough from the previous period will continue
its progression southeastward with sights on the Mid-Mississippi
and western Ohio Valley's as we step through Wednesday. Enough
trailing energy will feed into the backside of the trough allowing
for a bit more of a robust response compared to what transpires
upstream the prior evening. First round of convection will the
remnants of the overnight MCS with expected decay of the complex of thunderstorms as we step through Wednesday morning. Cold front will
also continue its progression south and southeastward through the
Ohio and Missouri Valley during the period with a bit more
latitudinal loss further west compared to downstream. By Wednesday
afternoon, we'll see the introduction of the shortwave into the
center of the CONUS lead to broader amplification of the longwave
trough positioned east of the Mississippi allowing for greater
large scale ascent focused over the western Ohio Valley back into
the confluent area of the Ohio and Mississippi River between the
MO/TN/IL area. This has been consistently depicted over the past
series of forecast runs with the end of the current 00z CAMs suite
also noting this particular zone as the more favorable area of
organized convection with multiple rounds anticipated.

After 00z, nocturnal LLJ will kick in across the Mississippi Valley
with the nose of the jet acting as a low-level convergent feature
and aiding in an increasing regional bulk shear to provide a
necessary element to organize and sustain convective development.
Forecast soundings via the NAMNest and ECMWF are consistent with
robust ascent within the mid-levels thanks to the amplifying
trough, as well as the added low-level convergence with the
arrival of the cold front and nose of the LLJ into the region. This
signature typically correlates to a focal point for heavy
convection with back-building potential until fropa is complete
leading to some heavier rainfall lingering for several hours before
the threat subsides. Considering PWATs between 2-2.25" centered
across the tri-state region outlined above, and the added ascent
factors in both the boundary layer and mid-levels (sfc-500mb),
there will likely be an area that sees a period of 1-2"/hr rainfall
for at least 3-6 hrs. leading to flash flood prospects carrying
overnight into early Thursday morning. Consistency in the signal
has allowed for a maintenance of the previous SLGT risk, however
some adjustment was made to convey more certainty across the area
between southeastern MO into southern IL and western KY/TN. Some
areas are liable to see 2-4" of rainfall with a max of up to 6"
plausible considering the environment at large.

Other areas of convection will line up along the front as it
progresses slowly southeast through the rest of the Ohio Valley,
entering areas that are still in recovery from the onslaught of
heavy rainfall the past 7 days. These storms are not anticipated to
be nearly as prolific as the past several days, and even not as
prolific as what will transpire upstream. That said, antecedent
soil moisture anomalies approaching the 95th percentile over a
large area, plus the threat of slow moving convection along the
front is more than sufficient for a MRGL risk carrying through
parts of KY/IN/OH with the eastern extent into portions of WV. This
whole region remain sensitive, so the forecast will be monitored
closely for any targeted upgrades if trends seem fit.

Kleebauer

...Southwest into the Central High Plains...

The previous forecast remains on track with the global
deterministic and newest 00z CAMs suite in agreement on scattered
thunderstorm activity likely to transpire Wednesday afternoon,
carrying into the evening hours with areas of the Front Range the
most notable for seeing more organized convection thanks to added
shear and regional ascent attributed to a shortwave proxy off the
Central Rockies. Synoptically, the evolution of the setup across
the Southwest and Front Range begins with an upper ridge centered
over the Four Corners, re- centering and amplifying while an
inverted trough pushes west on Wednesday. This will promote a more
favorable setup for monsoonal convection as a surge of
thermodynamics (PWs above 1.25" overlapping MUCAPE of 1000-2000
J/kg) lifting northward behind the inverted trough. At the same
time, weak shortwaves embedded within the flow and rotating around
the ridge will produce areas of locally enhanced ascent, which into
the improving thermodynamics suggests more widespread convective
activity is likely on Wednesday. While a more substantial risk for
greater coverage and intensity exists just beyond D2, a large MRGL
risk for excessive rainfall appears supported from the Deserts of
Arizona northeast into the Central High Plains of CO/KS. With
rainfall rates of 0.5-1"/hr likely at times, and mean storm motions
of just 5-10 kts, (higher in CO but with stronger bulk shear for
organization) this will support at least isolated instances of
flash flooding, especially over vulnerable terrain, urban areas, or
recently saturated soils. A MRGL risk remains in place for much of
the Desert Southwest into portions of the Central Rockies through
the Colorado Front Range.

Weiss/Kleebauer
$$
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