Mesoscale Precipitation Discussion 0141
NWS Weather Prediction Center College Park MD
1022 PM EDT Fri Apr 18 2025

Areas affected...eastern Oklahoma through southern/east-central
Missouri

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

Valid 190221Z - 190821Z

Summary...Several instances of flash flooding are possible through
08Z/3am this morning as convective coverage increases along/ahead
of a front through the discussion area. 

Discussion...Over the past hour, rapid thunderstorm development
has materialized both along and just northwest of a surface cold
front extending from near PVJ/Pauls Valley, OK northeastward to
near Joplin and Springfield, MO.  The storms were located in a
steep mid-level lapse rate environment, with ~7C/km H7-H5 rates
and 1.25-1.4 inch PW values supporting strong, quickly evolving
updrafts.  The orientation of the initiating front parallel to 50+
kt mean flow aloft was allowing for this initial convection to
train and produce spots of 1 inch/hr rain rates (especially in
northeastern Oklahoma), supporting localized flash flood potential
in the short term.

With time, continued evolution of convection into combinations of
lines/clusters and even supercells will allow for areas of
propagation to the right of mean flow.  Local rain rates of 1-1.5
inch/hr are expected, which should approach hourly FFG thresholds
(in the 1.5 inch/hr range - lowest in Missouri) over time.  The
tendency for storms to grow upscale and propagate eastward may
help to mitigate a larger-scale flash flood risk tonight, although
isolated to scattered instances of runoff are still expected where
convective training is more pronounced.  This risk will spread
northeastward into more of Missouri beginning from 03Z onward and
perhaps reach portions of Saint Louis and vicinity in the 07-10Z
timeframe.

Cook

ATTN...WFO...EAX...ICT...LSX...LZK...OUN...SGF...TSA...

ATTN...RFC...ABRFC...LMRFC...MBRFC...NCRFC...NWC...

LAT...LON   39079119 38529009 37659028 35739330 34069712
            34359777 35499688 36779552 38229352