377
AWUS01 KWNH 242313
FFGMPD
VAZ000-NCZ000-WVZ000-TNZ000-KYZ000-250500-

Mesoscale Precipitation Discussion 1050
NWS Weather Prediction Center College Park MD
713 PM EDT Tue Sep 24 2024

Areas affected...South-Central Appalachians

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

Valid 242311Z - 250500Z

SUMMARY...Threat for further thunderstorm development overnight
ahead of cold front may bring additional 2 to 3" resulting in
isolated flash flooding overnight.

DISCUSSION...Scattered supercells have developed east of the
pre-frontal convection over east-central KY and middle TN in the
broad warm sector west of the crest of the south-central
Appalachians. Recent rainfall estimates from KJKL are up to
1.5"/hr over far eastern KY. Sufficient moisture of 1.5 to 1.6" PW
and instability with MLCAPE 1000 to 1500 J/kg will continue to
allow redevelopment of activity this heavy. There are further
threats for flash flooding as the main pre-frontal convection
comes through later this evening along with topographical lift
from the western slopes of the south-central Apps. Deviant motion
has been noted from left-moving super cells, so cell mergers and
local upwind propagation will continue to be where the greatest
flash flood threat is into the overnight.

This area has rather low FFG, generally 1 to 1.5"/hr and around
2"/3hr. So overlap from ongoing activity and the next round
further raises the potential for flash flooding. Recent HRRR runs
have indicated generally 1 to 2" from both rounds, which helps
point to an isolated flash flood threat overnight.


Jackson

...Please see www.wpc.ncep.noaa.gov for graphic product...

ATTN...WFO...GSP...JKL...MRX...RLX...RNK...

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

LAT...LON   38268090 37298082 36138197 35498348 36318409
            37188367 38208261