MESOSCALE PRECIPITATION DISCUSSION 0422
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
703 AM EDT TUE OCT 14 2014
 
AREAS AFFECTED...PORTIONS OF THE FL PANHANDLE 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 141102Z - 141532Z
 
SUMMARY...A COUPLE BANDS OF THUNDERSTORMS ARE MOVING OVER AREAS
SATURATED BY OVERNIGHT CONVECTION.  WITH RAINFALL RATES UP TO 2"
AN HOUR ANTICIPATED, FLASH FLOODING IS POSSIBLE.

DISCUSSION...BROAD 850 HPA INFLOW OF 30-50 KNOTS CONTINUES TO
FOCUS AHEAD OF A COLD FRONT MOVING INTO THE WESTERN PANHANDLE,
WHICH HAS ALLOWED FOR PROGRESSIVE CONVECTIVE BANDS ACROSS THE
REGION.  PRECIPITABLE WATER VALUES ARE ~2", MAINLY IN THE VICINITY
OF A WEAK WARM FRONT.  AREAS OF 1000+ J/KG MOST UNSTABLE CAPE
CONTINUE AHEAD OF THE COLD FRONT ACROSS THE FL PANHANDLE.  BANDS
OF PRE-FRONTAL CONVECTION HAVE MOVED THROUGH THE PANHANDLE SINCE
LATE YESTERDAY, DROPPING UP TO 6" OF RAINFALL LOCALLY, WHICH
SHOULD HAVE SATURATED SOILS IN THE REGION.  

OVERNIGHT, THE REGION HAS WAVERED BETWEEN A LONGER DURATION FLOOD
AND A SHORTER DURATION FLASH FLOOD EVENT.  THE CONCERN IS THAT
SATURATING SOILS MAY BE TIPPING THE BALANCE TOWARDS A FLASH FLOOD
EVENT THIS MORNING.  THE AVAILABLE GLOBAL AND MESOSCALE GUIDANCE
HAS BEEN A FEW HOURS TOO SLOW WITH THE MOVEMENT OF THESE BANDS OF
CONVECTION, SO ATTEMPTED TO USE RAP MASS FIELDS AND AREAS WHICH
HAVE PREVIOUSLY RAINED TO HELP DEFINE THE AREA OF CONCERN, IN LIEU
OF THE  OUTDATED FLASH FLOOD GUIDANCE.  SOME COOLING HAS BEEN
RECENTLY NOTED IN SATELLITE IMAGERY, WHICH HAS LED TO AN INCREASE
IN THE HOURLY RAIN RATES PER RADAR IMAGERY EAST OF TALLAHASSEE AND
FARTHER WEST NEAR EGLIN AIR FORCE BASE.  HOURLY RAIN RATES UP TO
2" AN HOUR WITHIN BANDS OF THUNDERSTORMS COULD CAUSE FLASH
FLOODING OVER SATURATED AND CLAY SOILS ACROSS THE REGION OVER THE
NEXT SEVERAL HOURS, WITH MESOSCALE GUIDANCE INDICATING THE
POSSIBILITY OF AN ADDITIONAL 2-4" THROUGH 16Z.

ROTH

ATTN...WFO...JAX...MOB...TAE...

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

LAT...LON   31608463 31248309 29498330 29888411 29598484 
            29588536 29828553 30178597 30378647 31488615