• DAY3SVR: Nws Storm Predic

    From Weather Alert@618:250/1 to All on Mon Mar 29 14:24:00 2021
    ACUS03 KWNS 290707
    SWODY3
    SPC AC 290706

    Day 3 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0206 AM CDT Mon Mar 29 2021

    Valid 311200Z - 011200Z

    ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
    THE WESTERN GULF COAST...SOUTHEAST...SOUTHERN
    APPALACHIANS...CAROLINAS AND VIRGINIA...

    ...SUMMARY...
    Thunderstorm development will be possible on Wednesday from the
    western Gulf Coast northeastward into the Carolinas and Virginia.
    Strong wind gusts and hail will be the primary threats.

    ...Western Gulf Coast/Southeast/Southern
    Appalachians/Carolinas/Virginia...
    An upper-level trough is forecast to move eastward across the
    central U.S. on Wednesday. At the surface, a cold front is forecast
    to advance southeastward into the southeastern U.S. being positioned
    form the western Gulf Coast to the southern Appalachians by midday.
    As surface temperatures warm during the day, pockets of weak
    instability are expected to develop, with surface dewpoints ahead of
    the front in the lower to mid 60s F. Increasing instability and
    low-level convergence along and just ahead of the front will likely
    result in thunderstorm development during the afternoon. Near the
    front, deep-layer shear is forecast to be in the 45 to 55 kt range.
    This combined with steep low-level lapse rates will make isolated
    damaging wind gusts a possibility. Hail could also occur with the
    stronger cores. Any severe threat is expected to be marginal and
    confined to the mid to late afternoon when surface temperatures will
    be maximized.

    ..Broyles.. 03/29/2021

    $$
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  • From Weather Alert@618:250/1 to All on Sun Apr 4 09:22:00 2021
    ACUS03 KWNS 040728
    SWODY3
    SPC AC 040728

    Day 3 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0228 AM CDT Sun Apr 04 2021

    Valid 061200Z - 071200Z

    ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR CENTRAL KANSAS
    INTO SOUTHWEST MISSOURI AND ADJACENT PORTIONS OF OKLAHOMA AND
    ARKANSAS...

    ...SUMMARY...
    Severe thunderstorms are possible portions of the central Great
    Plains into the western Ozarks late Tuesday afternoon through
    Tuesday night.

    ...Central Great Plains into the Ozarks...
    A mid-level low and attendant trough, initially over western WY and
    the eastern Great Basin, will move east-southeastward to the central
    High Plains. A belt of strong cyclonically curved 500 mb flow will
    move through the base of the trough and overspread a destabilizing
    warm sector across the central and southern Great Plains. In the
    low levels, a surface cyclone over western KS will develop eastward
    and elongate as a cold front over the central High Plains surges
    southward into northwest TX and the northwest half of OK by early
    Wednesday morning.

    A capped but gradually moistening boundary layer will spread
    northward into northern OK and KS during the day on strengthening
    southerly low-level flow. Strong deep-layer ascent near the surface
    low will likely favor initial thunderstorm development during the
    afternoon. Steep 700-500 mb lapse rates (8-9 deg C/km) and strong
    flow will support storm organization with large hail and severe
    gusts the primary hazard. A strengthening LLJ during the evening
    over OK/KS and associated isentropic lift will probably lead to
    additional storms and the organization of a thunderstorm cluster
    moving east-southeast during the night into parts of southeast KS
    and adjacent parts of OK/AR/MO.

    Farther south across OK, thunderstorm development is less likely
    during the day owing to the aforementioned cap. Nonetheless, a low
    probability scenario for a storm or two southward along the dryline
    cannot be ruled out. It seems plausible the risk for isolated to
    scattered storms will focus overnight across northern and eastern OK
    as strong large-scale forcing promotes isolated to scattered storms.
    Hail/wind would be the primary risks with this activity.

    ..Smith.. 04/04/2021

    $$
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  • From Weather Alert@618:250/1 to All on Fri May 7 13:45:00 2021
    ACUS03 KWNS 070725
    SWODY3
    SPC AC 070724

    Day 3 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0224 AM CDT Fri May 07 2021

    Valid 091200Z - 101200Z

    ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
    CENTRAL/EAST TEXAS TO THE MID-SOUTH...

    ...SUMMARY...
    Isolated to scattered severe storms appear possible on Sunday from
    parts of central/east Texas to the Mid-South.

    ...Southern Plains to the Mid-South and Lower Ohio Valley...
    A low-amplitude shortwave trough should advance from the
    southern/central Plains to the lower/mid MS Valley and lower OH
    Valley through Sunday evening. A weak surface low over southwestern
    MO Sunday morning is forecast to develops towards the lower OH
    Valley in the same time frame, while a trailing cold front moves
    southeastward across parts of central/east TX, AR, and the
    Mid-South. A strong southwesterly low-level jet is forecast to shift
    quickly eastward from the Mid-South vicinity to the OH Valley by
    Sunday afternoon.

    Mainly elevated storms will probably be ongoing Sunday morning
    across portions of southern MO/IL in the warm advection regime
    associated with the low-level jet. In the wake of this early
    activity, low-level moisture should increase ahead of the
    southeastward-moving cold front. Mid to upper 60s surface dewpoints
    appear likely to be in place across much of the warm sector by
    Sunday afternoon. Diurnal heating of this moist low-level airmass
    should foster moderate to potentially strong instability ahead of
    the front, particularly across central/east TX into parts of
    northern LA and much of AR. Even though large-scale ascent across
    this region may remain fairly muted, most guidance indicates
    convection will develop along the cold front. Forecast deep-layer
    shear appears strong enough to support organized severe storms, with
    both large hail and damaging straight-line winds possible. Upscale
    growth into a line along the front may also occur. These storms
    should eventually weaken with eastward extent across the lower MS
    Valley as they outpace the better low-level moisture return and
    encounter a less unstable airmass.

    Farther north across parts of the mid MS Valley into the Lower OH
    Valley, instability should be weaker owing to the influence of the
    morning convection and slightly less low-level moisture return.
    Still, the presence of low to perhaps mid 60s surface dewpoints
    along and just east of the weak surface low suggest some potential
    for surface-based convection across this region. Various forecast
    soundings indicate strong shear in the low levels, but weak to
    minimal instability. Although some severe threat may materialize
    across parts of southern IL/IN into western/central KY Sunday afternoon/evening, this potential currently appears too limited to
    include any more than a Marginal Risk for these areas.

    ..Gleason.. 05/07/2021

    $$
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  • From Weather Alert@618:250/1 to All on Fri May 28 10:06:00 2021
    ACUS03 KWNS 280659
    SWODY3
    SPC AC 280658

    Day 3 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0158 AM CDT Fri May 28 2021

    Valid 301200Z - 311200Z

    ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR SOUTHEAST NEW
    MEXICO AND SOUTHWEST TEXAS...

    ...SUMMARY...
    Widely scattered severe thunderstorms are possible across the
    Permian Basin and southwest Texas. Large to very large hail and
    severe gusts are the primary hazards.

    ...Southern High Plains...
    A mid- to upper-level trough near southern CA Saturday morning will
    move east into southern AZ/northwestern Mexico by late Saturday
    night. A belt of moderately strong west-southwesterly 500 mb flow
    (35-40 kt) will nose eastward across northern Mexico into southern
    NM and southwest TX during the evening/overnight. Moist
    southeasterly upslope flow will maintain a seasonably moist airmass
    in the Permian Basin featuring 60s F dewpoints. Strong heating will
    result in steep 0-2 km lapse rates and a moderate to very unstable
    airmass by late afternoon from southwest TX into southeast NM
    (2500-3000 J/kg MLCAPE). Veering flow in the low to mid levels
    beneath 70 kt 250 mb flow, will result in a wind profile supporting
    supercells. By early evening, low-level shear is forecast to
    strengthen coincident with a strengthening LLJ over west TX and
    perhaps a narrow window of opportunity for a tornado risk with the
    stronger supercells. Upscale growth into a cluster or two will
    probably occur and this activity may persist into the late evening
    with severe gusts becoming the primary hazard.

    Elsewhere, isolated thunderstorms are possible across the FL
    Peninsula, eastern NC, and over the central High Plains.

    ..Smith.. 05/28/2021

    $$
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  • From Weather Alert@618:250/1 to All on Fri Jun 4 10:35:00 2021
    ACUS03 KWNS 040729
    SWODY3
    SPC AC 040727

    Day 3 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0227 AM CDT Fri Jun 04 2021

    Valid 061200Z - 071200Z

    ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER A PORTION
    OF THE UPPER MISSISSIPPI VALLEY AS WELL AS THE SOUTHERN HIGH
    PLAINS...

    ...SUMMARY...
    A few strong to severe storms with gusty winds and hail will be
    possible across a portion of the upper Mississippi Valley as well as
    the southern High Plains on Sunday.

    ...Upper Mississippi Valley region...

    A low-amplitude shortwave trough embedded within belt of stronger
    westerlies will move along the international border and through
    southern Manitoba and western Ontario during the day. A cold front
    will accompany this feature and move through the northern Plains and
    into upper MS Valley during the day. By late afternoon the front
    should extend from northwest MN southwest through eastern SD into
    western NE. A corridor of moderate instability is expected in the
    pre-frontal warm sector with 1500-2000 J/kg MLCAPE. The deeper
    forcing for ascent attending the shortwave trough will remain north
    of the international border, but frontal convergence might be
    sufficient to initiate a few storms by late afternoon, especially
    across MN. Storms that develop might become capable of producing a
    few locally strong wind gusts and hail through early evening before
    weakening as the surface layer begins to stabilize.

    ...Southern High Plains...

    Closed upper low currently situated over TX is forecast to drift
    slowly northward into OK Sunday. Modest northwest winds aloft will
    prevail upstream of this feature over the southern High Plains. A
    corridor of moderate instability will likely evolve where plume of
    steeper lapse rates overlaps the western fringe of richer low-level
    moisture across west TX. Potential will exist for a few storms to
    develop over the higher terrain and within the more deeply mixed
    regime across eastern NM and spread southeast. Southeasterly
    low-level winds beneath modest northwest winds aloft will contribute
    to 30-35 kt effective bulk shear. This environment will support some
    threat for large hail and locally strong wind gusts as storms spread
    southeast during the late afternoon through mid evening.

    ..Dial.. 06/04/2021

    $$
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