ACUS01 KWNS 301238
SWODY1
SPC AC 301236

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0736 AM CDT Wed Apr 30 2025

Valid 301300Z - 011200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST
TX INTO SOUTHWEST OK AND THE ARKLATEX...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM WEST-CENTRAL
MO ACROSS SOUTHERN IL INTO SOUTHERN IN...

...SUMMARY...
Scattered severe thunderstorms are possible on later today into this
evening from the southern Plains into the Lower Ohio Valley, with
the greatest risk expected across north-central Texas into the
ArkLaTex region. Large to very large hail, damaging winds, and
tornadoes are all possible, with some strong-tornado potential.

...Synopsis...
Early morning satellite imagery shows a mature convective complex
over western OK and northwest TX, another decaying convective
complex over southern MO, and a shortwave trough moving across the
Southwest. Recent surface analysis shows a mesolow associated with
western OK/northwest TX MCS over the SPS vicinity, with another,
more substantial low back southwest near SNK. An outflow boundary
from prior convection extends from south-central OK through
southeastern OK before becoming more diffuse and merging with the
stationary front over central AR.

The ongoing MCS is forecast to continue eastward/northeastward
throughout the day while the Southwest shortwave progresses into the
southern High Plains. Farther east, the stationary front that
extends from AR into the Mid-Atlantic is expected to begin
translating back northward as a warm front.

...North TX/Southern OK into the Arklatex and Mid-South...
The well-organized MCS currently tracking across southwest OK and
northwest TX is forecast to continue east-northeastward throughout
much of the period. The northern portion of this system will likely
remain progressive, moving through southern OK and north TX.
Damaging gusts and occasional hail will be possible with this system
throughout much of its lifecycle. Buoyancy decreases with eastern
extent, so the system should begin to lose intensity, but its
organized character limits the predictability of where that will
occur. Not only that, but downstream destabilization could lead to
potential reintensification/redevelopment along the outflow during
the late afternoon. Vertical shear will be modest, suggesting
reorganization into a severe convective line appears unlikely.

The southwestern portion of this MCS is expected to trail behind the
more forward-progression portion as it becomes more parallel to the
deep-layer shear vector. This orientation would likely keep deep
convection out of central/northeast TX before this afternoon. Storm
development appears probable across central TX as the surface low
and associated dryline shifts eastward ahead of the Southwest
shortwave trough. Development is possible ahead of this dryline
within the destabilized warm sector over northeast TX as well. Lapse
rates will be modest, but ample low-level moisture will still result
in moderate to strong buoyancy during the afternoon. Additionally, a
belt of stronger low-level flow is anticipated to persist,
supporting strong low-level shear and veering low-level hodographs.
The conditions support the potential for supercells capable of all
severe hazards, including tornadoes.

Eventual storm clustering could lead to development of a nocturnal
MCS that could eventually approach parts of the lower MS Valley,
with at least an isolated severe threat.

...West TX into Northwest TX/Southwest OK...
Additional strong to severe storms will be possible across parts of
west TX, in closer proximity to shortwave trough moving across the
southern High Plains. Cold temperatures aloft and steep lapse rates
will support a threat of hail and localized severe gusts, even
though deep-layer flow/shear will be more modest within this regime.
These storms may eventually spread toward southwest OK/northwest TX
before weakening.

...Parts of MS/OH Valleys...
Afternoon thunderstorm development is anticipated amid modest
low-level moisture advection in the wake of the convective cluster
currently moving through southwest MO. Modest buoyancy and shear
across the region suggest there is some potential for at least
transient storm organization in the vicinity of the frontal zone,
with an attendant threat for hail, locally damaging wind, and
possibly a tornado.

...Southern VA/northern NC...
Scattered storm development will be possible near the front across
parts of VA/NC. Deep-layer flow/shear will generally be weak, but
steep low-level lapse rates could support locally damaging outflow
winds with the strongest storms.

..Mosier/Jewell.. 04/30/2025

$$
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ACUS01 KWNS 171249
SWODY1
SPC AC 171248

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0748 AM CDT Sat May 17 2025

Valid 171300Z - 181200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS NORTH
TEXAS AND SOUTHERN OKLAHOMA...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
UPSTATE NEW YORK AND WESTERN NEW ENGLAND...

...SUMMARY...
Severe thunderstorms producing large to very large hail, damaging
gusts and a couple of tornadoes are expected across the southern
Plains. Additional severe storms are possible across the Northeast.

...Southern Plains Region...
Water vapor imagery depicts a pronounced southern stream upper-level
trough over the Baja Peninsula this morning, with evidence of a lead
impulse approaching southwest TX. This leading impulse will
contribute to ascent in the vicinity of a sharpening dryline across
Western North Texas/Oklahoma by early afternoon. To the east of the
dryline, extreme instability (MLCAPE in excess of 4000 J/kg) is
expected to develop given the moist low-level air mass and
relatively cool mid-level thermal profiles. With negligible CINH by
early/mid afternoon, thunderstorms are expected to develop along the
dryline and move east/northeast into North Texas and southern
Oklahoma. Supercells will be the dominant mode initially, with a
risk for very large hail (in excess of 3.5 inches), and damaging
gusts. Although low-level shear is not especially strong, some
tornado risk will exist given the magnitude of instability and
potential for storm-scale interactions. Eventual upscale growth into
a severe MCS is expected as storms continue to move across North
TX/southern OK this evening. Severe wind probabilities have been
increased across the Enhanced Risk area for the expectation of a
more concentrated corridor of damaging wind potential.

Across central/northwest OK, a narrowing plume of instability will
be present east of the dryline and south of an east-west oriented
frontal boundary. Within this moist sector, strong to extreme
instability and around 50 kts of deep-layer shear will support at
least isolated supercell storm development this afternoon over
central OK. Very large hail (3 inches or greater) will be possible,
in addition to damaging gusts. Tornado risk will be dependent on
storm interactions. Thunderstorm development over northwest OK is
more uncertain, however should a storm develop a supercell mode will
be favored with all hazards possible.

...Northeast...
Strong mid-level height falls will spread across much of the
northeastern U.S. today in response to the approaching Great Lakes
upper low. Large-scale ascent will increase with as the left-exit
region of the 500mb jet translates across PA. Scattered
thunderstorms, including supercells, are expected to develop
along/ahead of the synoptic cold front across upstate NY, with
subsequent movement expected into western New England. Multiple
rounds of thunderstorms are likely, with severe hail and winds as
the primary risks. A tornado or two cannot be ruled out with any
stronger and semi-discrete supercell. Please refer to Mesoscale
Discussion 836 for additional details on short-term expectations.

...Northern Utah Vicinity...
A Marginal Risk has been introduced across northern UT and vicinity
given expected higher concentration of storms within a deeply-mixed
boundary layer. Strong/severe gusts will be the primary severe risk.

...Lower Mississippi Valley/Southeast...
Thunderstorms continue from central MS into the western Carolinas at
13z, with occasional pulses of strong/severe cells. Isolated
stronger storms will remain possible as diurnal
heating/destabilization takes place in the presence of ample shear
for organized storms. However, with the line of convection oriented
generally parallel to the shear vector, any severe risk should be
isolated. Strong gusts will be the primary hazard.

..Bunting/Marsh.. 05/17/2025

$$
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