796
AWUS01 KWNH 011825
FFGMPD
ALZ000-MSZ000-LAZ000-012230-

Mesoscale Precipitation Discussion 0367
NWS Weather Prediction Center College Park MD
224 PM EDT Sat Jun 01 2024

Areas affected...southern LA/MS/AL

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

Valid 011823Z - 012230Z

SUMMARY...Slow moving/training and repeating of cells may generate
localized flash flooding across portions of the central Gulf Coast
through 23Z. Peak rainfall rates of 2 to near 3 in/hr will be
possible.

DISCUSSION...Visible satellite and regional radar imagery at 18Z
showed developing thunderstorms extending from between BTR and
MSY, eastward into far southern MS. These storms were forming
within a very moist and unstable environment with PWATs between
1.7 and 2.0 inches and MLCAPE of 2500-3500 J/kg with little to no
CIN via the 17Z SPC mesoanalysis. Visible satellite showed a
distinction between more developed cumulus to the south from less
concerning fair weather cumulus to the north across LA/MS with the
transition marked by a west-east oriented effective frontal
boundary associated with the leading edge of higher surface
dewpoints (middle-upper 70s) to the south. Aloft, flow was
modestly diffluent and divergent on the south side of an upper
level trough, progged to shift east through 00Z.

Thunderstorms are expected to continue to increase coverage
through the remainder of the afternoon with low level convergence
along the leading edge of deeper moisture, slowly edging north.
There is a relative lull in effective bulk shear across LA into
southern MS (~30 kt or less) which should limit storm
organization. However, given mean steering flow from west to east,
or parallel to the effective frontal boundary, there could be some
repeating and brief training of cells over the next several hours.
The environment is supportive of rainfall rates of 2 to 3+ in/hr
which could result in some areas of localized flash flooding.
Portions of the region have been wetter than average over the past
several days which may be a favorable ingredient for flash flood
development.

Otto

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

ATTN...WFO...JAN...LCH...LIX...MOB...

ATTN...RFC...LMRFC...SERFC...NWC...

LAT...LON   31498904 31168784 30068794 29458965 29569113
            29869186 30209220 30919206 31149068