• Heavy Rain/Flooding TX/OK

    From Mike Powell@618:250/1 to All on Thu May 30 08:49:00 2024
    AWUS01 KWNH 300948
    FFGMPD
    TXZ000-OKZ000-301545-

    Mesoscale Precipitation Discussion 0343
    NWS Weather Prediction Center College Park MD
    547 AM EDT Thu May 30 2024

    Areas affected...Portions of the TX Panhandle into Northwest TX
    and Southwest OK

    Concerning...Heavy rainfall...Flash flooding possible

    Valid 300945Z - 301545Z

    SUMMARY...Multiple rounds of heavy showers and thunderstorms this
    morning may result in a few instances of flash flooding.

    DISCUSSION...The latest GOES-E IR satellite imagery shows a couple
    of relatively concentrated MCS clusters traversing the southern
    High Plains from northeast NM into the TX Panhandle, and
    separately down to the southeast over northwest TX and far
    southwest OK. This convection has been generally tending to grow
    in organization over the last couple of hours and is being
    facilitated by the arrival of low-amplitude shortwave energy
    arriving over the High Plains downstream of a broader upper trough
    over the Western U.S.

    This energy though is interacting with a broad warm air advection
    regime with increasingly moist and unstable low-level south to
    southeast flow seen advancing up across much of the southern
    Plains region. With some low-level CIN in place, MLCAPE values are
    on the order of 1500+ J/kg in the vicinity of these convective
    clusters. The activity is also generally aligned north of a warm
    front returning northward across western and central TX.

    Over the next few hours, the aforementioned shortwave energy
    should favor convective sustenance with both convective clusters
    expected to drop generally southeastward into the persistent and
    slowly veering moist/unstable low-level flow. The veering of the
    low-level flow going through the mid-morning hours will be most
    pronounced across areas of northwest TX and the TX Panhandle which
    will be important as this will likely favor some convective
    regeneration and potentially some repeating cell-activity around
    the southern and southwest flanks of each convective cluster.
    Outflow boundaries in time will likely become better defined which
    in itself will also act as a catalyst for renewed convection.

    Rainfall rates with the stronger storms should reach 1 to 2
    inches/hour, and some localized storm totals especially across
    areas of northwest TX may reach 3 to 4 inches this morning since
    portions of this region will likely see impacts from both
    convective clusters. Some spillover of this convection through
    southwest OK will be expected as well and locally heavy totals
    possible here too.

    Some localized 3-hour FFG exceedance is suggested in the 00Z/06Z
    HREF guidance, and with the localized repeating nature of some of
    the cells, a few localized instances of flash flooding will be
    possible.

    Orrison

    ATTN...WFO...AMA...FWD...LUB...OUN...SJT...

    ATTN...RFC...ABRFC...WGRFC...NWC...

    LAT...LON 35340005 35049898 34559792 33979728 33139748
    32869846 33009958 33490100 34040164 34840163
    35250109

    = = =
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  • From Mike Powell@618:250/1 to All on Fri Jul 5 08:32:00 2024
    AWUS01 KWNH 050907
    FFGMPD
    TXZ000-OKZ000-051505-

    Mesoscale Precipitation Discussion 0563
    NWS Weather Prediction Center College Park MD
    506 AM EDT Fri Jul 05 2024

    Areas affected...TX Panhandle into West-Central and Southwest OK

    Concerning...Heavy rainfall...Flash flooding possible

    Valid 050905Z - 051505Z

    SUMMARY...Scattered to broken areas of convection will continue
    this morning across areas of the TX Panhandle down into
    west-central and southwest OK. Sufficiently high enough rainfall
    rates coupled with slow cell-motions may foster at least localized
    areas of flash flooding.

    DISCUSSION...GOES-E IR satellite imagery shows broken areas of
    cold-topped convection over areas of the TX Panhandle with the
    activity tending to expand further in coverage off to the east
    into areas of west-central to southwest OK.

    The activity is focused along an instability gradient north of a
    stationary front focused across areas of western and northern TX.
    MUCAPE values of 500 to 1000+ J/kg are in place and there is
    relatively divergent flow aloft working in tandem with a corridor
    of stronger low-level moisture convergence to help facilitate the
    development and expansion of the convection.

    Some additional increase in the concentration of convection may
    occur from the TX Panhandle down into southwest OK going through
    the mid-morning hours, and the cell-motions are expected to be
    rather slow which will favor some potential for locally excessive
    rainfall totals.

    The PWs are running about 2 standard deviations above normal over
    the region, and rainfall rates are expected to locally reach 1 to
    2 inches/hour with the stronger storms. The 00Z/06Z HREF guidance
    favors some spotty totals going through mid-morning of 2 to 4
    inches and this may result in a localized concerns for some flash
    flooding.

    Orrison

    ATTN...WFO...AMA...LUB...OUN...

    ATTN...RFC...ABRFC...NWC...

    LAT...LON 36380063 36199964 35599819 34699799 34239887
    34430077 34880216 35380274 35810283 36370216

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  • From Mike Powell@618:250/1 to All on Sun Nov 3 09:28:00 2024
    AWUS01 KWNH 030931
    FFGMPD
    TXZ000-OKZ000-031500-

    Mesoscale Precipitation Discussion 1116
    NWS Weather Prediction Center College Park MD
    430 AM EST Sun Nov 03 2024

    Areas affected...northern TX into southern OK

    Concerning...Heavy rainfall...Flash flooding possible

    Valid 030929Z - 031500Z

    Summary...An axis of training heavy rain is expected to impact
    portions of northern TX into southern OK through 15Z with rainfall
    rates of 1 to 2+ in/hr. Rainfall totals of 2 to 4+ inches are
    expected through 15Z along with possible flash flooding.

    Discussion...Looping regional radar imagery through 09Z showed a
    QLCS progressing eastward across OK at roughly 40-50 kt but the
    southwestern flank of this convective line has largely stalled
    across northwestern TX, between US 180 and US 380 to the north of
    Abilene. Area VAD winds at 850 mb showed 40-45 kt from the south
    across central to western TX, overrunning the rain-cooled airmass
    where 1000 to 2000+ J/kg MLCAPE was present along and south of the
    outflow boundary (per 09Z SPC mesoanalysis). In addition to the
    low level forcing in place, flow aloft was diffluent and
    divergent, within the left exit region of a RAP-estimated 110-120
    kt upper level jet max crossing Big Bend NP.

    Despite the typical diurnal cycle favoring weakening of the low
    level jet through 15Z, RAP forecasts suggest only slight weakening
    of the 850 mb winds (into the 30-40 kt range) as a shortwave
    trough axis over the southern AZ/NM border translates eastward
    this morning. However, infrared cloud tops have been warming
    across northwestern TX over the past hour, perhaps due to a
    combination of the intrusion of dry air aloft as seen on Layered
    PW imagery and weakening moisture flux.

    Despite the recent weakening, a flash flood threat will remain
    across the Red River Valley over the next few hours as areas of
    training will likely persist into the mid-morning hours with storm
    motions parallel to the low level axis of forcing. The threat for
    training and 1 to 2+ in/hr rates is expected to shift ENE across
    the Red River into portions of southern OK through 15Z along with
    additional rainfall totals of 2 to 4 inches (locally higher).
    Flash flooding will continue to be possible over the next few
    hours with an expected weakening of rainfall intensity and
    training potential toward the end of the MPD valid time (13-15Z).

    Otto

    ATTN...WFO...FWD...OUN...SHV...SJT...TSA...

    ATTN...RFC...ABRFC...LMRFC...WGRFC...NWC...

    LAT...LON 35269523 35099451 34269451 33389623 32939780
    32710002 33489970 34339837 34829718 35079643


    $$
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