AWUS01 KWNH 261401
FFGMPD
MSZ000-LAZ000-ARZ000-261900-

Mesoscale Precipitation Discussion 0320
NWS Weather Prediction Center College Park MD
1001 AM EDT Mon May 26 2025

Areas affected...Northern LA...Western & Central MS...Southeast AR...

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

Valid 261400Z - 261900Z

SUMMARY...Intense squall line along/ahead of MCV/Cold Pool will
track through areas having received heavy rainfall yesterday and
again this morning. An additional 1" in 30 minutes followed by
shield precip may reaggravate flooding conditions through early
afternoon.

DISCUSSION...Regional RADAR mosaic depicts a mature MCS with well
defined boundary features, with a strong bow/squall line extending
from the meso-low southwest of ELD along the state line
southwestward into the Piney Woods before becoming oriented west
to east across the Heart of TX. An effective warm front has been
established along the outflow boundary from yesterday's complex
across MS/AL. Solid southerly and southwesterly return flow from
the Gulf brings Tds in the the mid-70s and with active scattered
convection along it throughout the pre-dawn enhancing a meso-high
across E MS; the gradient has sharpened increasing moisture flux
convergence along it. Weakening low level flow has reduced
convergence but localized clusters, such as the one near HEZ have
allowed for focused convection to continue resulting in ongoing
flash flooding conditions even prior to the line. As such,
portions of southeast AR, Northeast LA and SW MS have seen
generally 1-2" with those enhanced hot-spots to 4", reducing
capacity of the upper soil column.

VWP shows a slow reduction of the LLJ toward 25kts which is
veering ahead of the squall line, but the forward speed driven by
1016mb meso-high and northeast shifting MCV into SW AR,
convergence will remain strong enough to maintain the northern
(southeast propagating) portion of the line. Total moisture over
2" and MUCAPE of 1000-1250 J/kg will allow to maintain solid
rainfall production. Rainfall rates up to 1.5"/hr are probable,
though only 15-30 minutes of duration will result in a quick
.75-1" in such short duration over the saturated soils that will
maintain any ongoing flash flooding or trigger a scattered
incident or two along the path generally along I-20. Potential
for flash flooding should reduce slightly toward central MS where
soils have not been as compromised as locations further southwest,
especially near Natchez, MS.

It should be noted that additional new stronger development is
probable along the downstream edge of the complex into S MS/AL
toward afternoon but this is less certain in timing/placement and
will watch trends closely for any additional MPD need.

Gallina

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

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

LAT...LON 33639133 33229018 32738938 32128904 30988945
30749001 31009111 31189214 31389305 31809355
32499352 33579296

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