Graphic for MPD #0057

Mesoscale Precipitation Discussion 0057
NWS Weather Prediction Center College Park MD
357 PM EST Sun Feb 11 2024

Areas affected...central Louisiana, central Mississipppi, central
Alabama

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

Valid 112056Z - 120256Z

Summary...An isolated flash flood threat continues across much of
the Deep South through 03Z.  Local convective training and cell
mergers could result in areas of excessive runoff - especially in
sensitive and/or urbanized areas.

Discussion...A mostly elevated MCS has held together across
central/northern Mississippi through the afternoon while finally
interacting with surface-based instability on its southern flank
over the past hour near/just northeast of Jackson.  Southwest of
this MCS, a trailing outflow extends from near Vicksburg, MS to
near Fort Polk, LA where it merges with a synoptic cold front. 
These boundaries have been a focus for renewed convective
development from near Jackson southwestward to far southeast
Texas, and localized training and cell mergers have allowed for
spots of 1-1.5 inch/hr rain rates to materialize espeically along
the Sabine River Valley.  Additional convection has materialized
over the open warm sector into central and southern Alabama, where
weak confluence and moderate surface-based instability has enabled
robust updrafts and spots of 1 inch/hr rain rates per MRMS.

With time, models and observations continue to indicate that both
warm-sector initiation and deep convection along aforementioned
boundaries will continue to support occasional mergers and/or
training of storms - especially from central Louisiana toward the
I-20 (and perhaps US 84) corridors in central Mississippi. 
Occasional 1-1.5 inch/hr rain rates are expected to continue,
which may exceeded FFGs on occasion especially in central MS where
1-2 inch/hr thresholds were noted.  These trends will continue to
support an isolated flash flood threat through 03Z, with perhaps
the highest threat existing along and a few counties north/south
of I-20 and portions of central Mississippi.  A separate, but more
isolated flash flood threat should exist farther away from the
outflow/cold front across Alabama, where isolated cells have now
begun to right-move and train very near Montgomery.

Cook

ATTN...WFO...BMX...FFC...JAN...LCH...LIX...MEG...MOB...SHV...

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

LAT...LON   33798776 33558531 32588519 31938568 31198792
            30559085 30379284 30759321 31729274 32449158
            33468995
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Last Updated: 357 PM EST Sun Feb 11 2024