Mesoscale Precipitation Discussion 0073
NWS Weather Prediction Center College Park MD
433 AM EST Wed Feb 28 2024

Areas affected...portions of the upper Ohio Valley and surrounding
areas

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

Valid 280931Z - 281500Z

Summary...Fast-moving convection across Indiana/Kentucky will
migrate through the discussion area over the next 3-6 hours.  A
modest increase in flash flood potential is expected, though the
overall threat is expected to remain isolated at best.

Discussion...Mid-level ascent across the Lower Ohio Valley has
finally interacted favorably with seasonably high warmth/moisture
located across much of the Ohio Valley to promote development of
bands of convection generally from near Dayton, OH southwestward
to near Paducah.  The storms were embedded in a warm sector
characterized by around 1000 J/kg MUCAPE (per SPC Mesoanalyses)
and 70-80 knot mean westerly flow between 850-300mb, promoting
fast storm motions (around 50 knots).  Despite the quick forward
speeds, a few structures were oriented favorably for localized
training/repeating and rain rates estimated at around 1 inch/hr
per MRMS.  The storms are currently located atop areas of mostly
1.5-2 inch/hr FFG thresholds, suggestive of a very isolated flash
flood threat in the near term (through 1030Z).

Over time, however, expanding convective coverage and movement
toward more moist soils and generally more sensitive ground
conditions (i.e., FFGs at around 1 inch/hr into Ohio and West
Virginia) suggests a gradual uptick in flash flood potential from
1030Z-1500Z.  Hillier terrain and sensitive low spots could be the
focus for this flash flood risk, especially if those spots happen
to underlie training convection that can foster better rain rates
for an hour or two.  Despite more favorable ground conditions with
eastward extent, the fast storm motions should still mitigate the
overall risk.

Cook

ATTN...WFO...CLE...CTP...ILN...JKL...LMK...LWX...PBZ...RLX...
RNK...

ATTN...RFC...MARFC...OHRFC...NWC...

LAT...LON   40788179 40748014 40287859 39567830 38567926
            38098073 37698395 37758576 38978526 40498354