• DAY1SVR: Enhanced Risk TX

    From Dumas Walker@21:1/175 to All on Tue May 28 09:53:00 2024
    ACUS01 KWNS 281251
    SWODY1
    SPC AC 281249

    Day 1 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0749 AM CDT Tue May 28 2024

    Valid 281300Z - 291200Z

    ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THROUGH EARLY
    TONIGHT FOR PARTS OF EAST...CENTRAL AND WEST TX...

    ...SUMMARY...
    Corridors of severe wind of 60-80 mph and occasional very large hail
    (in excess of 2 inches in diameter) can be expected with multiple
    convective clusters across east/southeast Texas and far southwest
    Louisiana through this afternoon, and from west into central Texas
    later this afternoon into tonight.

    ...TX/southwest LA through tonight...
    A complex situation is unfolding this morning across TX, with an
    initial, severe MCS (that evolved from earlier/elevated convection)
    surging southeastward from north central into east TX. This MCS has
    a history of measured 75-80 mph gusts and it will likely move along
    the strong buoyancy gradient near and east of the Trinity River.
    The MCS will be maintained by a corridor of mid-upper 70s dewpoints
    and extreme MLCAPE up to 4000 J/kg. Deep-layer vertical shear is
    strong enough to help maintain organization of the MCS, while the
    extreme buoyancy/steep lapse rate environment will also favor a
    continuation of strong downdrafts with the potential to produce
    additional gusts of 75-80 mph into southeast TX this afternoon
    (possibly including the Houston metro area).

    Farther west, outflow from the ongoing convection may help focus
    additional storm development this afternoon into west central and
    central TX, or could serve as an effective eastern boundary to
    storms that form and move east of the southern High Plains and
    Trans-Pecos. Expect a mix of supercells with very large hail (in
    excess of 2 inches in diameter) and some upscale growth into
    clusters/line segments with the potential to produce severe outflow
    winds of 60-75 mph from later this afternoon into early tonight.

    ...Elsewhere...
    A midlevel shortwave trough over MN this morning will progress
    southeastward toward IL by this evening. Ascent preceding the
    midlevel trough, cool midlevel temperatures and lingering low-level
    moisture could be sufficient for a few storms to produce marginally
    severe hail and/or strong outflow gusts this afternoon/evening from
    southern WI to northern IL/northwest IN. Farther west, a midlevel
    trough will move inland over WA/OR and the associated deep
    baroclinic zone will approach the northern Rockies. Moisture will
    be limited in this zone, but some high-based convection could
    produce isolated strong-severe outflow gusts late this
    afternoon/evening.

    ..Thompson/Grams.. 05/28/2024

    $$
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  • From Dumas Walker@21:1/175 to All on Thu May 30 08:51:00 2024
    ACUS01 KWNS 301241
    SWODY1
    SPC AC 301240

    Day 1 Convective Outlook
    NWS Storm Prediction Center Norman OK
    0740 AM CDT Thu May 30 2024

    Valid 301300Z - 311200Z

    ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
    INTO EARLY TONIGHT FOR THE TX SOUTH PLAINS AND BIG COUNTRY...

    ...SUMMARY...
    Scattered severe storms with large hail up to baseball size,
    damaging winds of 60-75 mph, and a couple of tornadoes are expected
    this afternoon into tonight from west into central Texas. More
    isolated severe storms will be possible today from the Red River
    Valley into east Texas, and into southwest Texas.

    ...Southern Plains through tonight...
    A complex scenario is unfolding this morning with multiple, small
    thunderstorm clusters ongoing across southern KS/northwest OK,
    northwest TX and the TX Panhandle. The warm sector across
    TX/southern OK has recovered during the past 24 hours, with
    boundary-layer dewpoints into the upper 60s to northwest TX and the
    upper 70s along the TX coast. The latter two clusters will likely
    be the most influential today while moving east-southeastward along
    the north edge of the richer moisture/buoyancy, with the potential
    for occasional severe outflow winds of 60-70 mph and isolated large
    hail of 1-1.75 inches in diameter from north into east TX today.
    Convective outflow is expected to spread southwestward in the wake
    of these morning storms, which will help focus additional severe
    storm development this afternoon/evening across the TX South Plains
    and Big Country.

    Strong buoyancy (MLCAPE of 2500-3500 J/kg), steep midlevel lapse
    rates, and effective bulk shear of 35-40 kt will support supercells
    with initial storm development this afternoon in the ENH area. The southern-most/more discrete storms will have the greater potential
    to produce very large hail near baseball size (2.75"), along with a
    couple of tornadoes if storms can interact favorably with zone of
    somewhat enhanced low-level moisture/shear along the residual
    outflow boundary. Upscale growth of these storms into another MCS
    is probable tonight, with occasional damaging winds and large hail
    continuing well into the overnight hours into central/north TX.

    ...KS/CO/NE through tonight...
    Prior convective overturning and lingering convection this morning
    in KS cast doubt on any specifics regarding the severe threat north
    of the ongoing TX storm clusters. Residual low-level moisture and
    surface heating in cloud breaks later today could result in
    sufficient destabilization for a few strong-severe storms with
    hail/wind. However, vertical shear will also be relatively weak in
    most areas along and south of the slow-moving front from CO to NE,
    which combined with the effects of prior convection could tend to
    limit the overall severe threat. Will maintain much of the original
    SLGT risk area into KS/CO, but confidence in the forecast is low.

    ..Thompson/Grams.. 05/30/2024

    $$
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