Mesoscale Precipitation Discussion 1232
NWS Weather Prediction Center College Park MD
1001 PM EDT Wed Sep 09 2026

Areas affected...portions of the Ohio Valley & Central
Appalachians

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

Valid 100200Z - 100800Z

Summary...A band of showers and thunderstorms continues sagging
southward into the Ohio Valley.  Hourly rain amounts to 2.5" with
local totals to 4" are possible, which could lead to flash
flooding across partially saturated soils and rough topography.

Discussion...A line of showers and thunderstorms extends from
southeast IN into southwest PA with another segment with heavier
rainfall across north-central PA.  Precipitable water values are
1.6-2.1" in this area per GPS data.  CIN has set in and MUCAPE
across the region is 500+ J/kg in eastern areas and 2000+ J/kg in
western areas.  Effective bulk shear of 30-45 kts has been
organizing convection.  The thunderstorms lie within a confluent
zone/elevated front.

The guidance suggests that the thunderstorm activity should have
some longevity, particularly within areas with higher instability
which will take longer to erode closer to the central Ohio Valley.
 Based on the parameters above, hourly rain amounts to 2.5" with
local totals to 4" are possible, which would be more problematic
in the areas of lower flash flood guidance values across the Upper
OH Valley, which based on the mesoscale guidance would be sooner
rather than later.  Isolated to widely scattered flash flooding is
possible here.

Roth

ATTN...WFO...CTP...ILN...IND...JKL...LMK...PBZ...RLX...

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

LAT...LON   40747967 40377843 38628060 37808569 39158559
            39638338 40248131