MESOSCALE PRECIPITATION DISCUSSION 0278
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1123 PM EDT FRI JUN 26 2015
 
AREAS AFFECTED...PORTIONS OF THE UPPER OH VALLEY 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 270322Z - 270922Z
 
SUMMARY...SHOWERS AND THUNDERSTORMS ACROSS IN AND OH ARE EXPECTED
TO CONTINUE OVERNIGHT.  FLASH FLOODING IS POSSIBLE OVER SATURATED
SOILS.

DISCUSSION...A ZONE OF WIND CONVERGENCE BETWEEN THE SURFACE AND
850 HPA IS ACTING AS THE FOCUS FOR EFFICIENT SHOWERS AND
THUNDERSTORMS.  RADAR IMAGERY SHOWS POCKETS OF 0.5-1.5"/HOUR RAIN
RATES, WHICH HAS BEEN CAUSING FLASH FLOODING OVER SATURATED SOILS.
 MUCAPES IN THE REGION ARE 100-500 J/KG (HIGHER IN SOUTHERN OH),
WHILE PRECIPITABLE WATER VALUES LIE NEAR 1.75" PER GPS INFORMATION
AND RECENT RAP ANALYSES.  FOR THE TIME BEING, INFLOW INTO OH HAS
BEEN INTERRUPTED BY AN MCV MOVING TOWARDS THE OH/WV BORDER.

THE MESOSCALE GUIDANCE INDICATES LOCAL AMOUNTS OF 1-2" ARE
EXPECTED OVER THE NEXT SEVERAL HOURS, WHICH COULD OCCUR IN A SHORT
PERIOD OF TIME ON A LOCAL BASIS.  RAP FORECAST FIELDS SHOW A
SLIVER OF 500+ J/KG MUCAPES, WHICH COULD LEAD TO LOCALLY HEAVY
RAINS IN SUCH A SATURATED ATMOSPHERE.  AS THE MCV MOVES AWAY FROM
THE REGION, INFLOW INTO OH SHOULD LEAD TO A REJUVENATION OF
RAINFALL ACROSS CENTRAL AND EASTERN PORTIONS OF THE STATE.  FLASH
FLOOD GUIDANCE VALUES REMAIN QUITE LOW OVER PORTIONS OF OH AND IN
AS SOILS ACROSS THE REGION HAVE BEEN SATURATED BY RECENT RAINS. 
PER SOUTHERN REGION, 30 DAY RAIN TOTALS IN THIS AREA HAVE BEEN
ROUGHLY 6-12".  FLASH FLOODING REMAINS POSSIBLE OVERNIGHT.

ROTH

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

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

LAT...LON   41238103 40768015 40118009 39628049 39098187 
            39298362 39228560 39218701 40348608 40968455 
            41128330