Mesoscale Precipitation Discussion 1249
NWS Weather Prediction Center College Park MD
324 AM EST Tue Nov 25 2025

Areas affected...northern LA/MS border into central MS/northern AL

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

Valid 250823Z - 251400Z

Summary...While the overall flash flood coverage looks to decrease
later this morning across MS and AL, concerns remain for localized
2 to 3+ inch totals from hourly rainfall of 1 to 2+ inches. A
threat of flash flooding will linger through 14Z.

Discussion...08Z radar imagery showed an axis of strong
thunderstorms extending from western LA near DRI, northeastward
into central/northern MS. The most powerful section of this axis
was in western MS, between TVR and JAN, where some of the
strongest low level winds were observed with near 50 kt at 850 mb
from the south. A low level confluence axis from western LA into
northern MS remained a focus for thunderstorms, out ahead of a
potent vorticity max located over AR and within the
diffluent/divergent right-entrance region of an associated upper
level jet max which extended across the MS Valley into the Midwest.

Cloud tops on infrared satellite imagery have shown trends toward
warming overall over the past 2-3 hours, but bursts of colder
cloud tops remained, such as what was occurring over western MS at
08Z. A reservoir of 500-1500 J/kg MLCAPE remained from central MS
into central/southern LA with up to ~1000 J/kg MUCAPE northward
into western TN. Short term forecasts from the RAP show that as
the vorticity max over AR continues to translate toward the ENE,
925-850 mb winds will veer over southern MS/AL which will have the
effect of weakening the existing axis of confluence across the
region through 12Z. However, remnant low level
convergence/confluence coincident with strong upper level ascent
will continue a threat for heavy rain and periods of training. The
environment will still be capable of localized rainfall rates over
2 in/hr but 1 to 2 inches in an hour will be more common.
Therefore, through 14Z, a localized flash flood threat will remain
from the LA/MS border into central MS and central to northern AL
where 2 to 3+ inches of rain could fall in a 2 to 3 hour window,
with the greatest concern for flash flooding across urban or
otherwise sensitive/low-lying areas.

Otto

ATTN...WFO...BMX...FFC...HUN...JAN...LCH...LIX...MEG...MOB...

ATTN...RFC...ALR...ORN...NWC...

LAT...LON   34998668 34728550 33428524 32468689 31268959
            30999128 31309200 31769195 32099144 32569074
            33528925 34128831