MESOSCALE PRECIPITATION DISCUSSION 0368
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
307 PM EDT TUE JUN 21 2016
 
AREAS AFFECTED...CENTRAL APPALACHIANS 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 211906Z - 220006Z
 
SUMMARY...THUNDERSTORMS ARE EXPANDING IN COVERAGE AND BEGINNING TO
SHOW SIGNS OF CELL TRAINING.  WITH HOURLY RAIN RATES UP TO 2"
POSSIBLE, FLASH FLOODING IS POSSIBLE.

DISCUSSION...WARM AIR ADVECTION EAST OF A MESOSCALE WAVE ACROSS
NORTHERN KY IS CAUSING THUNDERSTORMS TO EXPAND IN COVERAGE, WITH
OVERSHOOTING TOPS NOTED ON VISIBLE IMAGERY.  PRECIPITABLE WATER
VALUES OF 1.6-1.8" LIE ACROSS THE REGION PER GPS VALUES.  SLIGHTLY
CONVERGENT INFLOW AT 850 HPA OF 20-30 KTS IS TAPPING MLCAPES OF
2000-2500 J/KG FROM CENTRAL AND EASTERN KY INTO THE REGION.

THE MESOSCALE/CAM GUIDANCE ADVERTISES LOCAL AMOUNTS IN THE 2-3"
RANGE, WHICH COULD FALL QUICKLY.  THE ENVIRONMENTAL CONDITIONS
SUPPORT HOURLY RAIN RATES UP TO 2", WHICH IF CELL TRAINING
PERSISTS LONG ENOUGH, COULD EXCEED THE EXPECTATIONS OF THE
MESOSCALE GUIDANCE.  SINCE THE KY CONVECTION APPEARS TO BE
EMBEDDED IN THE INSTABILITY POOL, CELL TRAINING IS MOST LIKELY
THERE UNTIL THE INSTABILITY IS EXHAUSTED.  ORGANIZED CONVECTION
SHOULD CONTINUE TO DROP SOUTHEAST AT 30-40 KTS.  THE SIGNAL IN THE
06Z SSEO NEIGHBORHOOD PROBABILITIES FOR EXCEEDING THE THREE HOUR
FLASH FLOOD GUIDANCE IS STRONGEST THROUGH 23Z, THOUGH AVAILABLE
INSTABILITY COULD KEEP IT GOING AN HOUR OR TWO LONGER.  AS FLASH
FLOOD GUIDANCE IN THE REGION IS MODEST, AND THERE IS RUGGED
TOPOGRAPHY IN THE AREA, FLASH FLOODING IS POSSIBLE.

ROTH

ATTN...WFO...ILN...JKL...LMK...MRX...RLX...RNK...

ATTN...RFC...LMRFC...MARFC...OHRFC...SERFC...

LAT...LON   38588258 38427991 36908030 36418222 36378313 
            36858400 37318477 38168510