AWUS01 KWNH 290233
FFGMPD
FLZ000-TNZ000-ALZ000-MSZ000-LAZ000-290830-

Mesoscale Precipitation Discussion 1203
NWS Weather Prediction Center College Park MD
931 PM EST Sat Dec 28 2024

Areas affected...Central Gulf Coast...Mid-South

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

Valid 290230Z - 290830Z

SUMMARY...Strong to severe thunderstorms associated with an
eastward advancing QLCS will continue to foster some potential for
areas of flash flooding going into the overnight hours.

DISCUSSION...The latest GOES-E IR satellite imagery in conjunction
with dual-pol radar shows a well-defined QLCS continuing to
advance off to the east across large areas of the Mid-South with
an extension essentially from northern MS south-southwestward down
into southeast LA. This continues to be associated with a strong
mid-level trough ejecting out of the Lower MS Valley and lifting
toward the Mid-South as it gradually takes on a neutral to
slightly negative tilt. Enhanced deep layer ascent and shear
continues to interact with a strong southerly low-level jet of 40
to 60+ kts and this will continue to drive a well-organized axis
of convection downstream across much of the South going through
the overnight hours.

MLCAPE values of 1500 to 2500 J/kg are noted across southeast LA
into far southern MS, and this coupled with higher PWs reaching
over 1.5 inches should tend to drive heavier rainfall rates across
this area with the more organized convective cells that will be
crossing this region over the next several hours. The convection
in general across the central Gulf Coast region including
southeast LA, southern MS and southern AL may tend to take on more
of a southwest to northeast orientation going through 06Z which
will facilitate some areas of cell-training.

Farther to the north, the instability does drop off rather
considerably, and especially for areas up across northern MS,
northern AL and through middle TN, but with such strong dynamical
forcing crossing this region, there should still be at least some
broken QLCS activity that fosters heavy rainfall. This portion of
the overall convective axis is certainly more progressive though
which will tend to keep the overall rainfall potential a bit more
limited.

Rainfall rates with the stronger and more organized storms, and
especially the supercell activity closer to the central Gulf
Coast, will still be capable of reaching 1.5 to 2.5 inches/hour.
For areas that do see cell-training, some additional rainfall
amounts of 2 to 4 inches will be possible overnight. This may
drive at least some pockets of flash flooding and especially
around the more sensitive urban corridors.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!=
DZ3fjg!66qJBdcM3qSWnWivv0F8k5hcl4Ewq1Kk7lTRWu4iMEUXLiuVSl6OCxLGAI7I6L6dgqMn=
-S6pPSdzuszfomkmTBntI2U$  for graphic product...

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

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

LAT...LON   35668714 35168590 33308571 31228642 30218757=20
            29908868 29528996 29249100 29469199 30089196=20
            30999050 32408972 34238929 35248854=20

=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to
https://lists.illinois.edu and use the "Unsubscribe" link.  Otherwise email
Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.20-Linux