MESOSCALE PRECIPITATION DISCUSSION 0002
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
945 PM EST THU FEB 20 2014
 
AREAS AFFECTED...SOUTHEAST IN & SOUTHWEST OH 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 210245Z - 210545Z
 
SUMMARY...A QUICK-MOVING BAND OF THUNDERSTORMS IS ABOUT TO MOVE
OVER AN AREA SATURATED BY RECENT SNOW MELT.  WITH ANOTHER BAND OF
THUNDERSTORMS APPROACHING FROM KY, REGIONAL FLASH FLOODING IS
POSSIBLE ACROSS SOUTHWEST OH.

DISCUSSION...STRONG VERTICAL WIND SHEAR WITHIN THE LOWER
TROPOSPHERE -- ON THE ORDER OF 60 KTS BETWEEN THE SURFACE AND 850
HPA -- HAS CAUSED A BAND OF STRONG THUNDERSTORMS TO CRUISE QUICKLY
THROUGH SOUTHERN IN NEAR AND SOUTH OF A WARM FRONT, APPROACHING
SOUTHWEST OH.  DIVERGENCE IS EXCELLENT TO THE SOUTHEAST OF A DEEP
CYCLONE LOCATED IN SOUTHWEST WI.  PRECIPITABLE WATER VALUES ARE ON
THE ORDER OF 1.25 INCHES, AT THE 99TH PERCENTILE FOR MID TO LATE
FEBRUARY.  CAPE VALUES ARE QUITE LOW, UNDER 500 J/KG, WHICH WOULD
NORMALLY NOT FEED A REGIONAL FLASH FLOOD EVENT.  HOWEVER, THREE
HOURLY FLASH FLOOD GUIDANCE VALUES ARE QUITE LOW DUE TO RECENT
SNOW MELT, ROUGHLY 0.50-0.75 INCH.  RADAR ESTIMATES ARE CURRENTLY
PEAKING IN THIS NEIGHBORHOOD PER HOUR, THOUGH SURFACE OBSERVATIONS
HAVE NOT RECORDED 0.30" PER HOUR AS OF YET.  WITH ANOTHER BAND OF
SHOWERS AND THUNDERSTORMS APPROACHING FROM CENTRAL KY, IT IS
POSSIBLE THAT A COUPLE BATCHES OF HEAVY RAINFALL COULD IMPACT THE
SATURATED SOILS OF SOUTHWEST OH.  DESPITE THE LOW CAPES, BELIEVE
REGIONAL FLASH FLOODING IS POSSIBLE IN THIS REGION OVER THE NEXT
FEW HOURS.

ROTH

ATTN...WFO...ILN...LMK...IWX...IND...

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

LAT...LON   38418595 38688614 39578576 40668531 40618370 40178284
            38988318 38568409 38418595