Graphic for MPD #0035

Mesoscale Precipitation Discussion 0035
NWS Weather Prediction Center College Park MD
623 PM EST Fri Jan 26 2024

Areas affected...portions of southeast TX & southwest LA

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

Valid 262322Z - 270522Z

Summary...Showers and thunderstorms are slowly growing in coverage
across southeast TX and southwest LA.  Hourly rain totals to 2.5"
and local amounts near 4" are possible, which could lead to
isolated to widely scattered instances of flash flooding.

Discussion...Showers and thunderstorms are developing ahead of an
upper level low moving across northern TX near an 850 hPa warm
front, with convection appearing to develop quicker/more broad
scale than indicated in the latest mesoscale guidance. 
Precipitable water values are exceeding 1.5".  MU CAPE is 500-1500
J/kg per SPC mesoanalyses, sufficient for convection with heavy
rainfall.  Effective bulk shear is 50-60 kts, which has allowed
for an organized convective cluster or two across southeast TX as
of late.

The expectation is for cell coverage to continue to increase as a
surface low deepens as it moves up the Upper Texas coast,
increasing boundary layer moisture convergence across the region,
which should lead to broader scale instances of hourly rain totals
up to 2.5", particularly where cells train, mesocyclones develop,
or cells merge.  Hourly rain totals to 2.5" with local amounts to
4" are anticipated, which is above the available mesoscale
guidance.  This would lead to isolated to widely scattered
instances of flash flooding.

Roth

ATTN...WFO...HGX...LCH...SHV...

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

LAT...LON   31659282 30949199 30369239 29829294 29449434
            28909538 29419596 30169581 30729512 31309412
           
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Last Updated: 623 PM EST Fri Jan 26 2024