MESOSCALE PRECIPITATION DISCUSSION 0164
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
341 PM EDT SUN MAY 01 2016
 
AREAS AFFECTED...PORTIONS OF WEST VIRGINIA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 011940Z - 020140Z
 
SUMMARY...SHOWER AND THUNDERSTORM DEVELOPMENT IS EXPECTED TO RENEW
SHORTLY ACROSS PORTIONS OF WV. CONSIDERING SATURATED SOILS, AND
HOURLY RAIN RATES UP TO 1.25" BEING POSSIBLE, FLASH FLOODING IS
POSSIBLE.

DISCUSSION...RECENT SATELLITE IMAGERY SHOWS AN ENHANCING CUMULUS
FIELD STATEWIDE AS THE ATMOSPHERE BEGINS TO RECOVER FROM EARLY
MORNING CONVECTION.  THIS IS OCCURRING SOUTH OF AN UPPER LEVEL
VORTICITY MAXIMUM ACROSS SOUTHEAST ONTARIO AND AHEAD OF ANOTHER
SYSTEM ACROSS SOUTHEAST IA.  PRECIPITABLE WATER VALUES OF 1-1.25"
INHABIT THE REGION PER RECENT GPS VALUES.  THE FLOW IS NEARLY
UNIDIRECTIONAL OUT OF THE WEST-SOUTHWEST, WITH VAD WIND PROFILES
SHOWING 15 KT INFLOW OUT OF THE WEST-SOUTHWEST ACROSS THE REGION. 
A POOL OF INSTABILITY EXISTS ACROSS KY WITHIN THE WARM SECTOR,
WITH SPC MESOANALYSES INDICATING 1000-1500 J/KG OF MLCAPE.

CONVECTION IS EXPECTED TO MOVE INTO THE REGION FROM THE NORTHWEST
AS COLD POOLS FORM IN ASSOCIATION WITH THE LINE OF CONVECTION
CURRENTLY ACROSS NORTHERN OH.  CONVERGENCE AT 850 HPA IS EXPECTED
TO INCREASE WITH TIME OVER WV, WHICH SHOULD ENHANCE CONVECTIVE
COVERAGE LOCALLY.  OTHER CURRENTLY WIDELY SCATTERED THUNDERSTORM
ACTIVITY SHOULD ATTEMPT TO BROADEN IN COVERAGE AS IT APPROACHES
FROM KY.  SHORT PERIODS OF TRAINING AND CELL MERGERS ARE EXPECTED
TO BE THE MAIN HEAVY RAIN THREAT AS POTENTIALLY ORGANIZED ACTIVITY
FROM THE NORTHWEST INTERACTS WITH PULSE ACTIVITY FORMING MORE
LOCALLY.  THE 12Z SSEO NEIGHBORHOOD PROBABILITIES SHOW THE HIGHEST
RISK FOR HEAVY RAINFALL BETWEEN 21-02Z.  WHILE INSTABILITY SHOULD
WANE NEAR AND AFTER SUNSET DUE TO ONGOING CONVECTION AND THE LOSS
OF DAYTIME HEATING, RAP GUIDANCE SUGGESTS AN INCREASE TO THE
LOW-LEVEL INFLOW LATER TONIGHT, WHICH WILL NEED TO BE WATCHED IN
CASE INSTABILITY IS GREATER THAN FORECAST.  CAM GUIDANCE SUGGESTS
LOCAL AMOUNTS OF 1-2" ARE ANTICIPATED, WHICH COULD FALL QUICKLY
DURING POSSIBLE CELL MERGERS OR AREAS OF SHORT CELL TRAINING AS
HOURLY RAIN RATES COULD REACH 1.25".  OVER SATURATED SOILS IN
RUGGED TERRAIN, THIS COULD LEAD TO FLASH FLOODING.

ROTH

ATTN...WFO...JKL...LWX...PBZ...RLX...RNK...

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

LAT...LON   39677995 39237942 38397970 37728027 37308048 
            37038115 37238156 37828240 38308261 38728257 
            39288126 39578075 39618063