MESOSCALE PRECIPITATION DISCUSSION 0253
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
217 PM EDT FRI JUN 01 2018

AREAS AFFECTED...CENTRAL AND EASTERN WV...WESTERN VA AND MD

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 011816Z - 012300Z

SUMMARY...CONVECTION IS EXPECTED TO GRADUALLY INCREASE THROUGH THE
AFTERNOON IN RESPONSE TO APPROACHING UPPER VORT MAX. LOW FLASH
FLOOD GUIDANCE DUE TO RECENT HEAVY RAINS WILL LEAD TO A RISK FOR
FLASH FLOODING.

DISCUSSION...A HIGHLY MOIST (PWATS IN THE 1.6 TO 1.8 INCH RANGE)
AND MODESTLY UNSTABLE (MLCAPES 500 TO 1000 J/KG) AIR MASS IS IN
PLACE ACROSS THE CENTRAL APPALACHIANS AND MID-ATLANTIC REGION
SOUTH OF A SURFACE FRONT. LATEST SATELLITE IMAGERY CLEARLY SHOW A
MID/UPPER-LEVEL VORT MAX TRAVERSING KENTUCKY EARLY THIS AFTERNOON,
MOVING EAST-NORTHEASTWARD.

SHOWERS AND THUNDERSTORMS ARE EXPECTED TO INCREASE IN COVERAGE
THROUGH THE AFTERNOON ACROSS THE OUTLINED AREAS AS THE
MID/UPPER-LEVEL VORT MAX APPROACHES, ENHANCING LIFT ACROSS THE
REGION. ENVIRONMENT SHOULD BE SUPPORTIVE OF RAINFALL RATES OF
1-1.5 IN/HR, AND LATEST HI-RES GUIDANCE SHOW THE POSSIBILITY FOR
LOCALIZED RAINFALL AMOUNTS EXCEEDING 2 INCHES THROUGH THE
AFTERNOON. RECENT HEAVY RAINS HAVE LED TO SATURATED GROUND,
ESPECIALLY ACROSS WESTERN PORTIONS OF VA AND EXTREME EASTERN WV,
AND FFG VALUES ARE WELL BELOW 1 IN/HR ACROSS THESE AREAS. THUS,
RUNOFF WILL BE QUICK TO INCREASE WITH ADDITIONAL HEAVY RAINS, AND
FLASH FLOODING IS POSSIBLE.

RYAN

ATTN...WFO...AKQ...LWX...PBZ...RLX...RNK...

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

LAT...LON   39677806 39617754 39337740 38657785 37977816
            37357898 37238012 37458092 37938129 38598114
            39158063 39547990 39667908