MESOSCALE PRECIPITATION DISCUSSION 0264
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
356 PM EDT MON AUG 11 2014
 
AREAS AFFECTED...PORTIONS OF OH 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 111955Z - 120000Z
 
SUMMARY...THUNDERSTORMS ARE INCREASING IN NUMBER AND INTENSITY
ACROSS OH, WITH INCREASING ORGANIZATION POSSIBLE BEFORE CAPE
VALUES FADE.  FLASH FLOODING IS POSSIBLE OVER AREAS OF LOW FLASH
FLOOD GUIDANCE.

DISCUSSION...A FRONTAL WAVE ACROSS NORTHWEST OH HAS SPURRED 25-30
KTS OF 850 HPA INFLOW INTO MUCH OF OH.  MOST UNSTABLE CAPE VALUES
OF 1000-2000 J/KG INHABIT THE REGION, PARTICULARLY NEAR AND
SOUTHWEST OF A WARM FRONT.  PRECIPITABLE WATER VALUES OF NEAR
1.75" LIE IN THE REGION, WHICH SUPPORTS HOURLY RAINFALL RATES UP
TO 2".  SEVERAL LOCATIONS ACROSS SOUTHERN KY OVER THE PAST 4-5
HOURS MEASURED RAINFALL OF 1.4-1.5" WITHIN AN HOUR.  THESE
CONDITIONS MEET THE CRITERIA FOR THE WET MULTI-CELL ENVIRONMENT.

AREAS NEAR AND AHEAD OF THE COLD FRONT SHOULD SEE CONVECTION WITH
INCREASING ORGANIZATION OVER THE NEXT FEW HOURS, BEFORE CAPES
ACROSS THE REGION FADE BY 00Z PER THE LATEST RAP RUNS.  THERE WAS
A SIGNAL IN THE 12Z SSEO NEIGHBORHOOD PROBABILITIES FOR >50%
CHANCE OF EXCEEDING THE THREE HOUR FFGS IN THE REGION LATE THIS
AFTERNOON.  WITH HOURLY RAIN RATES UP TO 2", AND LOCAL AMOUNTS OF
2-4" INDICATED BY THE MESOSCALE GUIDANCE WHERE CELLS TRAIN, FLASH
FLOODING IS CONSIDERED POSSIBLE.

ROTH

ATTN...WFO...PBZ...RLX...CLE...ILN...LMK...IWX...

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

LAT...LON   39198197 38788269 38558433 38928519 40208457 41278408
            41398284 41238204 40618145 39728163 39198197