Mesoscale Precipitation Discussion 0125
NWS Weather Prediction Center College Park MD
300 AM EDT Sat Apr 05 2025

Areas affected...Ark-La-Tex through the Mid-South

Concerning...Heavy rainfall...Flash flooding likely

Valid 050700Z - 051300Z

Summary...Convection to continue with rainfall rates of 1-3"/hr
and 6 hour localized totals of 3-6". Numerous to widespread flash
flooding to continue.

Discussion...A blocking pattern on the synoptic scale continues to
allow for a persistent region uplift via favorable upper-level
divergence. At the surface, convective initiation usually occurs
in the vicinity of the quasi-stationary front (in this case also
accompanied by strong frontogenesis). These storms have a steady
supply of moisture from the Gulf via an unusually strong and
persistent low-level jet (30-50 kts at 925-850 mb). Going forward,
the corridor most favored to receive heavy rainfall is
characterized by MU CAPE of 1250-1750 J/kg, a ribbon of near
record high precipitable water of 1.6-1.9 inches (well above the
max moving average for LZK, as a 2.0" reading has never been
recorded in April), and deep layer (0-6 km) shear of 40-60 kts.

Looking ahead, a hi-res model consensus suggest a narrow corridor
of 3-6" of rainfall is possible over the next 6 hours as the front
remains stalled in a highly favorable environment for renewed
convection capable of producing rainfall rates of 1-3"/hr. The 00z
HREF indicates high probabilities (50-70%) for localized 3"
exceedance (40-km neighborhood) from southwest AR through far
western TN and the MO Bootheel. While it is a good thing that the
bulk of the heavy rainfall over the past 24 hours has occurred to
the west of the main area of concern (though some portions of the
Ark-La-Tex are among those that have already received 3"+), 6 hour
Flash Flood Guidance values still generally range from 2.0-3.0".
As a result, continued numerous to widespread flash flooding is
likely. Should some of the more extreme depictions of localized
5"+ totals occur (as shown by more recent HRRR runs as well),
significant, life threatening flash flooding will be possible.

Churchill

ATTN...WFO...LZK...MEG...OHX...PAH...SGF...SHV...

ATTN...RFC...ABRFC...LMRFC...NCRFC...OHRFC...NWC...

LAT...LON   37998815 37618751 36748746 36048839 35668889
            34869011 34289110 33799202 33169337 32999405
            33149447 33709474 34379432 34909361 35659255
            36319153 36819079 37488950