791
AWUS01 KWNH 300208
FFGMPD
LAZ000-TXZ000-300607-

Mesoscale Precipitation Discussion 0342
NWS Weather Prediction Center College Park MD
1007 PM EDT Wed May 29 2024

Areas affected...Southeast TX...Southwest LA

Concerning...Heavy rainfall...Flash flooding likely

Valid 300207Z - 300607Z

SUMMARY...Slow-moving areas of heavy showers and thunderstorms
will tend to persist for a few more hours and will likely result
in some additional instances of flash flooding.

DISCUSSION...A shortwave trough advancing into the Lower MS Valley
continues to interact with a quasi-stationary front draped across
the northwest Gulf Coast region involving southeast TX and
southwest LA. Ongoing cold-topped convection across the region has
been showing signs of backbuilding over the last couple of hours
and remains embedded within a very moist and unstable environment.

MLCAPE values in vicinity of the front still remain locally as
high as 2000 to 3000 J/kg with PWs running upwards of 2 inches.
This coupled with locally focused frontal convergence and
relatively divergent flow aloft with the shortwave energy has been
promoting the persistence of some of these cells which have been
slow-moving and locally repeating over the same area.

The latest hires model guidance has been handling the ongoing
areas of convection very poorly, but the latest radar and
satellite imagery coupled with the environmental conditions
suggest that there may be some persistence of the convection for a
few more hours.

Rainfall rates have already been on the order of 2 to 2.5"/hour,
and with the slow cell-motions and focus near the front, some
additional spotty totals of 3 to 5 inches cannot be ruled out.
Therefore, some additional areas of flash flooding will be likely
over the next few hours.

Orrison

...Please see www.wpc.ncep.noaa.gov for graphic product...

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

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

LAT...LON   31339448 31199394 30929361 30589349 30409324
            30119305 29779313 29739371 29719423 29879495
            30149553 30399579 30759588 31039574 31259526