AWUS01 KWNH 231336
FFGMPD
MSZ000-LAZ000-TXZ000-231935-

Mesoscale Precipitation Discussion 0215
NWS Weather Prediction Center College Park MD
935 AM EDT Sat May 23 2026

Areas affected...Far Eastern TX...Central and Southern LA...Far
Southwest MS

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

Valid 231335Z - 231935Z

SUMMARY...Expanding areas of heavy showers and thunderstorms, with
some localized cell-training will result in an increasing flash
flood threat through the mid-afternoon hours. Rainfall rates of 2
to 3 inches/hour are expected, with localized totals of 3 to 5
inches possible.

DISCUSSION...GOES-E satellite imagery and radar shows some small
scale MCS activity over far eastern TX along with an embedded MCV
that will be moving east into areas of western LA over the next
few hours. The latest surface data suggests a surface
trough/outflow boundary near the southern LA coast that extends
west-southwest back toward the Upper TX coast.

Meanwhile, the airmass is moderately buoyant with a nose of MLCAPE
values reaching 1500 to 2000+ J/kg across far eastern TX and
across much of western LA in association with modest, but
persistent southerly flow off the Gulf ahead of the upstream
convection. Moisture is heavily entrenched through the column
based off the latest OSPO ALPW data, with PWs overall running up
to near 1.75 inches.

The approaching convection and associated MCV energy is expected
to interact with this surface trough near the Gulf Coast, and
favor a general increase in warm air advection/isentropic ascent
that coupled with the nose of instability should favor an increase
in the coverage of heavy showers and thunderstorms. The latest
Corfidi vector analysis suggests at least some low-end threat for
backbuilding and training convection over the next several hours
as the convection increases across areas of central and southern
LA, and perhaps areas as far northeast as southwest MS.

High rainfall rates are expected that could reach 2 to 3
inches/hour with the stronger convective cores, and with any
cell-training, some localized storm totals going through early to
mid-afternoon could reach 3 to 5 inches. FFG is rather high across
the region overall, with moderate soil moisture (50 to 70 percent)
in the 0-10cm layer according to NASA SPoRT. However, with the
high rainfall rates and localized storm total potential, some
areas of flash flooding will tend to become likely over the next
several hours. This will especially be the case for the more
sensitive urban corridors.

Orrison

ATTN...WFO...JAN...LCH...LIX...SHV...

ATTN...RFC...FWR...ORN...NWC...

LAT...LON   31979285 31679154 31059027 30288969 29688969
            29369007 29269094 29589253 29629308 29789379
            30719441 31249432 31819377

$$
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