MESOSCALE PRECIPITATION DISCUSSION 0314...CORRECTED
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
915 PM EDT SAT JUN 04 2016
 
CORRECTED FOR TYPOS

AREAS AFFECTED...CENTRAL VA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 050110Z - 050410Z
 
SUMMARY...THUNDERSTORMS ARE STARTING TO FORM WITHIN A WARM AIR
ADVECTION REGIME ACROSS THE REGION.  WITH HOURLY RAIN RATES UP TO
2", AND LOCAL AMOUNTS OF 4-7" POSSIBLE, FLASH FLOODING IS POSSIBLE.

DISCUSSION...THERMAL BOUNDARIES ACROSS NC AND VA ARE ACTING AS
FOCI/BOUNDARIES FOR CONVECTION TO FORM ALONG AND OVERRUN ACROSS
THE REGION.  OF NOTE IS A NEW AREA OF THUNDERSTORMS ACROSS
WEST-CENTRAL VA, FORMING AHEAD OF AN OLD COMPLEX ACROSS WV WHICH
MAY CONTAIN AN MCV.  INFLOW AT 850 HPA IS ~ 20 KTS, WITH MLCAPES
REMAINING 1500-2500 J/KG ACROSS SOUTHERN VA, WITH MUCAPES IN THE
2000-3000 J/KG RANGE.  PRECIPITABLE WATER VALUES ARE IN THE 1.8-2"
RANGE PER GPS VALUES.

RAP MASS FIELDS INDICATE THE BOUNDARY LAYER MOISTURE CONVERGENCE
SHIFTS NORTHWARD TOWARDS THE POTOMAC WITH TIME AND THAT LOW-LEVEL
INFLOW SHOULD CONTINUE TO SLOWLY INCREASING OVER THE NEXT SEVERAL
HOURS.  CIN COULD CONTINUE TO EXPAND ALONG THE BOUNDARIES IN THE
REGION ALLOWING THE CONVECTION TO SHIFT NORTHWARD SOMEWHAT AS
WELL.  THE CONCERN IS THAT SHORT PERIODS OF CELL TRAINING COULD
OCCUR ALONG THIS NEW CONVECTIVE LINE, THOUGH CONVECTION TO THE
SOUTH COULD WIPE OUT THE INSTABILITY POOL OVER THE NEXT 3-4 HOURS,
WHICH WILL BE WATCHED.  HRRR RUNS HAVE BEEN EMPHATIC WITH AMOUNTS
ACROSS NORTH-CENTRAL VA, WITH INDICATIONS FROM THE OPERATIONAL AND
TWO PARALLEL RUNS OF 4-7", WHICH COULD FALL QUICKLY.  CELL MERGERS
AND SHORT PERIODS OF TRAINING ARE THE MAIN CONCERN.  HOURLY RAIN
RATES COULD EXCEED 2", WHICH COULD LEAD TO FLASH FLOODING,
PARTICULARLY IN URBAN AREAS.

ROTH

ATTN...WFO...AKQ...LWX...RNK...

ATTN...RFC...MARFC...SERFC...

LAT...LON   38727742 38057640 37227683 37197978 37688018 
            38627913