AWUS01 KWNH 120928
FFGMPD
MSZ000-LAZ000-ARZ000-TXZ000-121526-

Mesoscale Precipitation Discussion 0029
NWS Weather Prediction Center College Park MD
427 AM EST Wed Feb 12 2025

Areas affected...much of Louisiana, central/southern Mississippi,
and a small part of east Texas

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

Valid 120926Z - 121526Z

Summary...Convective bands will continue to increase and grow
upscale into clusters and lines while moving eastward across the
discussion area. A few areas of 1-2 inch/hr rain rates are
expected, which should pose a flash flood risk especially near
sensitive areas.

Discussion...Over the past hour or so, radar mosaic imagery has
depicted a distinct uptick in convective activity across east
Texas and Louisiana. The increase in convection is likely tied to
a dramatic increase in southerly 850mb flow along the Sabine River
Valley (into the 40-60 kt range) along with attendant
convergence/ascent. The eastward movement of a distinct mid-level
shortwave trough and steep lapse rates aloft were also
contributing factors to the increase in convection. Most storms
are elevated above a cool stable boundary layer, although mergers
and growth into linear segments with localized training have
already been observed near/just east of Lufkin, where spots of 1
inch/hr rain rates were already estimated via MRMS.

These convective trends are expected to continue, with
observations and CAMs both suggestive of upscale growth into one
or two dominant complexes that move eastward across the region.
Many cell mergers are anticipated and localized training will
remain a distinct possibility. These factors should contribute to
occasional 1-2 inch/hr rain rates at times as storms move eastward
through the discussion area. These rates should approach FFG
thresholds - especially along an axis from Lufkin to Greenville to
Columbus where prior rainfall has contributed to wet soils and
<1.5 inch/hr FFG thresholds. Prolonged rainfall along and south
of this axis (i.e., greater than 1 hour of heavy rainfall) may
also result in flash flooding. This threat is expected to persist
through 15Z, with occasional convective redevelopment in east
Texas indicated in the models throughout the morning.

Cook

ATTN...WFO...HGX...JAN...LCH...LIX...MEG...SHV...

ATTN...RFC...LMRFC...SERFC...WGRFC...NWC...

LAT...LON 33888837 33218839 32128857 31239008 30539215
30489469 31609498 32489388 33409101 33838960

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