AWUS01 KWNH 270501
FFGMPD
MSZ000-LAZ000-ARZ000-271100-

Mesoscale Precipitation Discussion 1196
NWS Weather Prediction Center College Park MD
1201 AM EST Fri Dec 27 2024

Areas affected...Southwest and Central LA...Western and Central MS

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

Valid 270500Z - 271100Z

SUMMARY...A broken axis of heavy showers and thunderstorms will
continue to foster a localized threat for some flash flooding
overnight across portions of southwest to central LA through
western and central MS.

DISCUSSION...The latest GOES-E IR satellite imagery shows a
vigorous shortwave trough and compact low center transiting the
Lower MS Valley which continues to foster a rather well-organized,
but broken axis of heavy showers and thunderstorms. The activity
has waned somewhat over the last couple of hours as the stronger
mid and upper-level dynamics begin to lift away from the area of
greater instability pooled closer to the Gulf Coast, but the
low-level flow remains rather strong and convergent. In fact, the
area VWP data continues to show a 40 to 50+ kt low-level jet
surging northward up toward the Mid-South from the Gulf Coast and
this is maintaining a corridor of strong moisture transport and
convergence along and just ahead of a cold front.

MUCAPE values of 1000 to 1500 J/kg are still noted across areas of
southwest LA which taper down to 500 to 1000 J/kg across central
LA and into far southwest MS. The level of effective bulk shear
that is in place remains quite strong and is locally exceeding 50
kts which is still favoring a fair degree of convective
organization with the band of thunderstorms including some
supercell structures. These stronger cells will continue to have
the capability of producing very heavy rainfall rates that will
locally reach 1.5 to 2.5 inches/hour, and this will be aided by
PWs of near 1.5 inches and the aforementioned low-level jet.

The 00Z HREF guidance suggests that some southwest to northeast
training of these more organized cells may still occur at least
locally going through the overnight hours, with some spotty swaths
of 2 to 4 inch rainfall totals possible. As a result, the
convective activity is expected to still foster a localized threat
for some flash flooding and especially within any of the more
urbanized corridors.

Orrison

...Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!=
DZ3fjg!8AYKJQYCJzdlGJ1DnlsKVi-y-Vy0y68r4TY_Gx05VUkCCrk_D2j8_DfV9ZoNz4PbNAeT=
_RwPP91ja-S6tHrJH66gD4o$  for graphic product...

ATTN...WFO...JAN...LCH...LIX...MEG...SHV...

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

LAT...LON   33929018 33838931 33338915 32638945 32049000=20
            31549046 30729121 29619243 29509306 29759358=20
            30539289 31749210 33299114=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