194
AWUS01 KWNH 021344
FFGMPD
MSZ000-LAZ000-021900-

Mesoscale Precipitation Discussion 0373
NWS Weather Prediction Center College Park MD
944 AM EDT Sun Jun 02 2024

Areas affected...Southern Louisiana

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

Valid 021343Z - 021900Z

SUMMARY...Scattered heavy thunderstorms over southern Louisiana
will continue to develop and spread southeast through midday with
localized flash flooding possible through 18Z.

DISCUSSION...Regional radar indicates thunderstorms continue to
develop on the eastern extend of a low-level convergence boundary
that extends from North Texas to the Mouth of the Mississippi
which is east of an upper-ridge axis over west Texas. Hourly
rainfall estimates from KHDC has been up to 1.5" in and around
Baton Rouge. Newer activity to the south/west has become more
dominant over the past hour, but renewed activity is possible over
the outlook area. Included in this discussion is the area east of
Lafayette which saw 4-7" of rain Sunday afternoon, so it is still
quite sensitive to additional rainfall.

This area in LA is at the intersection of ample Gulf moisture (PWs
1.9" per RAP, GPS, and 12Z raobs from KLIX and KLCH) and an
instability gradient with 500 J/kg MLCAPE in southern Miss and
2500 J/kg over SW LA. Deep layer WNWly flow around 25kt is over
the area which should allow activity to expand east as it expands
into the greater instability to the south.

Recent HRRRs have struggled to initialize and maintain this
activity, but given the ingredients mentioned above and continued
light Sly flow around 10kt maintaining the elevated moisture,
further heavy thunderstorm development with hourly rainfall of
1-2" is likely. 1hr FFG is generally 2.5 to 3" outside of
particularly sensitive areas, so flash flooding should be rather
localized. Stratiform rain has occurred so far over the New
Orleans metro, though the forecast instability gradient and mean
layer flow should raise the risk for heavy rain there through
midday.


Jackson

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

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

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

LAT...LON   31199151 30749094 30479069 30058988 29689038
            29719111 30169206 30539248 31169222