Graphic for MPD #0056

Mesoscale Precipitation Discussion 0056
NWS Weather Prediction Center College Park MD
1011 AM EST Sun Feb 11 2024

Areas affected...northern Louisiana, southeastern Arkansas,
portions of northern and central Mississippi

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

Valid 111510Z - 112110Z

Summary...A conditional, isolated flash flood threat is evolving
across the discussion area as an organized convective complex
enters northwestern Louisiana.  Wet soils from prior runoff and
brief, heavy downpours could promote excessive runoff in a few
areas.

Discussion...Much of the outlined discussion area has experienced
2-4 inches of rainfall over the past 24 hours, resulting in wet
soils and very low FFG thresholds generally along an axis from
near Lake Providence, LA to Columbus, MS.  Meanwhile, an organized
MCS was approaching the Texas/Louisiana border near Shreveport,
and additional showers were persisting within a warm-advection
regime from central Louisiana to near Jackson, MS. The ongoing
precipitation was located just south of the axes of wettest
soils/lowest FFGs, although with showers/storms gradually moving
northeastward toward the areas of wet soils, current thinking is
that an isolated flash flood threat should begin to emerge in the
next couple of hours.

The overall magnitude of flash flood risk is in question, however.
 The convective complex near the Shreveport area is already
outperforming several high-res models -- likely due to the well
organized nature of the MCS and associated cold pool dynamics. 
With the surface warm front across central LA (and attendant
SB/MUCAPE axis) expected to lift northward, some concern exists
that at least isolated heavier rainfall (exceeding 0.5 inch/hr
rates) will spread northward into the wetter areas containing
lowered FFGs.  Areas of 0.5-2 inch rainfall totals are expected
with this activity for as long as convection holds together -
especially near and north of the I-20 corridor.  Flash flood
potential is expected to increase over time.

Cook

ATTN...WFO...JAN...LZK...MEG...SHV...

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

LAT...LON   34488923 34138830 32968839 31919051 31679325
            32239399 32899354 33339302 33819171
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Last Updated: 1011 AM EST Sun Feb 11 2024