Mesoscale Precipitation Discussion 0894
NWS Weather Prediction Center College Park MD
344 PM EDT Tue Sep 25 2018

Areas affected...Southern IN...central/eastern KY

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

Valid 251943Z - 260113Z

Summary...In an anomalously moist environment, thunderstorms
tracking into areas of low Flash Flood Guidance (FFGs) may lead to
flash flooding through this afternoon.

Discussion...Latest water vapor imagery showed a shortwave trough
across southwest Indiana moving east/northeast. At the surface,
broad southerly to southwesterly  flow has continued a flux of
high moisture characterized by PWATs in the 1.8 to nearly 2.0
inches per latest RAP mesoanalysis and blended TPW. MLCAPE values
have risen to around 1500 J/kg this afternoon with peak heating.
Latest radar returns from KVWX and KLVX showed clusters of
thunderstorms producing heavy rainfall with rates of 1 to 2 in/hr.

Latest runs of the HRRR have consistently shown these broken
clusters of showers and thunderstorms moving east/northeast
through southern Indiana and central KY into the northern
Bluegrass region through late afternoon. There is some potential
for training convection, especially across southern Indiana and
north central into northern KY. Additional rainfall of 1 to 2
inches will be possible with some localized higher amounts.

Finally, all of this activity is moving into an area of very low
FFG with 1-hr values of around 1 inch or less generally east of
Interstate 65 with the lowest values across the Bluegrass region
into northern Kentucky. Latest AHPS analysis shows the last 7 days
running 400 to 600 percent of normal. Area streams and rivers are
running high, so additional rainfall could lead to flash flooding
quickly.

Taylor

ATTN...WFO...ILN...JKL...LMK...PAH...

ATTN...RFC...OHRFC...

LAT...LON   39098417 38958384 38338374 37798389 37428427
            37118543 36978690 37498757 38058730 38408683
            38698585 38838533