Mesoscale Precipitation Discussion 0024
NWS Weather Prediction Center College Park MD
458 PM EST Thu Feb 06 2025

Areas affected...portions of KY and southwest VA

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

Valid 062157Z - 070357Z

Summary...Showers and thunderstorms within a saturated atmospheric
column over saturated soils are expected to lead to hourly rain
totals to 1.5" and local amounts to 3".  This could lead to flash
flooding over saturated soils and urban areas.

Discussion...Recent radar imagery shows quick-moving but scattered
showers and thunderstorms forming and moving through western KY at
the present time.  They are elevated in nature and forming on the
back side of a frontal zone with a few surface waves on the south
side of a broad shortwave trough in the Great Lakes, utilizing
500-1000 J/kg of MU CAPE.  Other activity to the southeast is much
closer to the surface front.  At the moment, the flat wave in
western TN is closest to the back edge of the convection. 
Precipitable water values of 0.75-1.25" lie across the region
within a cool air mass, leading to almost complete saturation. 
Effective bulk shear is ~50 kts, which is enough for both linear
convective organization and mesocyclone formation.

Flash flood guidance values are fairly low, roughly 1" in three
hours -- within the past 24 hours, 1-3" of rain fell in this area.
 With the expectation of 0.5"+ an hour totals, possibly as high as
1.5" in an hour, expected over the next several hours as the
storms propagate generally east-southeast parallel to thickness
lines, flash flood guidance exceedance could occur in scattered
spots where cells can train/two or more mesocyclones can align. 
The progressive frontal boundary and quick cell movement should
keep rain amounts from getting exceptionally high.  Hourly totals
to 1.5" with local amounts to 3" are the expectation, which could
lead to flash flooding in urban areas and over saturated soils and
hilly topography.

Roth

ATTN...WFO...JKL...LMK...MRX...OHX...PAH...RLX...RNK...

ATTN...RFC...LMRFC...OHRFC...NWC...

LAT...LON   38228453 37108114 36598259 36368416 36528789
            38218643