AWUS01 KWNH 271255
FFGMPD
PAZ000-MDZ000-VAZ000-WVZ000-OHZ000-INZ000-271853-

Mesoscale Precipitation Discussion 0257
NWS Weather Prediction Center College Park MD
854 AM EDT Wed May 27 2026

Areas affected...portions of Indiana, Ohio, West Virginia, western
Maryland, and southwestern Pennsylvania

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

Valid 271253Z - 271853Z

Summary...Flash flood potential will continue through at least
18Z/2p eastern today.

Discussion...Scattered convection continues to remain focused
along and just north of a warm frontal zone located from central
Indiana eastward though northern West Virginia. Along and south of
this boundary, near 70F dewpoints were supporting areas of
500-1000 J/kg MUCAPE along with 1.6 inch PW values.  These
thermodynamics were supporting briefly heavy rainfall due to
localized training despite appreciable storm motions (around 30
knots or so).  Spots of 1 inch/hr rain rates were noted over West
Virginia and in western Ohio, which were approaching or even
exceeding FFG thresholds on a localized basis (<0.75/hr in spots).

The overall regime should continue through at least 18Z/2p today
and likely beyond.  The warm frontal zone will move very little
today while weak mid-level waves and subtle convergence along the
front support redevelopment of convection.  Occasional training
bands will readily exceed FFG thresholds on an isolated to
scattered basis, and an appreciable coverage/number of flash flood
instances are expected given the regime and sensitivity of ground
conditions across the region.  Areas of rainfall totals reaching 3
inches are possible through 18Z, especially with convective
coverage expected to increase due to surface
heating/destabilization expected through the morning.

Cook

ATTN...WFO...CLE...CTP...ILN...IND...IWX...LWX...PBZ...RLX...

ATTN...RFC...RHA...TIR...NWC...

LAT...LON   40998239 40828009 40377813 40137789 39497770
            39157782 38747857 38467979 38618174 39288398
            39508616 40178658 40838612 40978465

$$
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