MESOSCALE PRECIPITATION DISCUSSION 0005
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
224 PM EDT SUN MAR 16 2014
 
AREAS AFFECTED...PORTIONS OF THE FL PANHANDLE 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 161823Z - 170023Z
 
SUMMARY...A SLOWLY PROGRESSIVE CONVECTIVE BAND OVER THE FLORIDA
PANHANDLE IS EXPECTED TO SLOW DOWN FURTHER OVER THE NEXT SEVERAL
HOURS AS IT PROGRESSES TOWARDS/THROUGH THE SOUTHERN AND EASTERN
PORTIONS OF THE FL PANHANDLE.  REGIONAL FLASH FLOODING IS POSSIBLE
OVER THE NEXT SEVERAL HOURS IN THIS REGION.

DISCUSSION...AN OUTFLOW BOUNDARY FORCED BY CONVECTION ACROSS THE
FL PANHANDLE CONTINUES TO PROGRESS INTO THE CENTRAL FL PANHANDLE. 
PER THE TAE RADAR, RAINFALL RATES OF 1-2 INCHES PER HOUR ARE STILL
BEING DETECTED WITHIN THIS RAIN BAND.  PRECIPITABLE WATER VALUES
REMAIN IN THE NEIGHBORHOOD OF 1.75 INCHES, NEAR THE 95TH
PERCENTILE FOR MID-MARCH.  CAPES UPSTREAM IN THE GULF OF MEXICO
REMAIN IN THE 1000-1500 J/KG RANGE, PER THE 12Z ARW GUIDANCE.  PER
RADAR AND SATELLITE IMAGERY, THE WESTERN EDGE OF THE PRECIPITATION
SHIELD HAS BEEN RELATIVELY STATIONARY DURING THE PAST COUPLE HOURS
AND THE THUNDERSTORM BAND EXTENDS WELL SOUTHWESTWARD INTO THE GULF
OF MEXICO, WHICH COULD BE DUE TO THE INFLUENCE OF A MID-LEVEL
SHORTWAVE SWINGING ACROSS NORTHERN MEXICO.

WHILE RAINFALL RATES HAVE BEEN SLOWLY DECREASING THE PAST FEW
HOURS, A FEW FACTORS IMPLY REGIONAL FLASH FLOODING REMAINS
POSSIBLE.  INFLOW AT 850 HPA WEAKENS FROM 50 KTS TO 40 KTS PER THE
17Z RAP GUIDANCE, WHICH SHOULD LESSEN THE FORWARD PROGRESSION OF
THE CONVECTIVE LINE.  THIS WAS BORNE OUT IN THE 12Z GFS GUIDANCE,
WHICH SHOWS CORFIDI VECTORS IN THE REGION OF AROUND 5 KTS, WHICH
INCREASES THE THREAT OF CELL TRAINING.  LOW-LEVEL SHEAR DROPS DOWN
TO 25-30 KTS, WHICH SHOULD CONTINUE TO SUPPORT MULTI-CELLULAR
CONVECTION.  UPSTREAM CAPES IN THE GULF OF MEXICO REMAIN STABLE
OVER THE NEXT SEVERAL HOURS, AND ARE HIGH ENOUGH TO SUPPORT A WET
MULTI-STORM ENVIRONMENT.  THE NON-RAP MESOSCALE GUIDANCE IS
ADVERTISING LOCAL 3-7" RAIN AMOUNTS BETWEEN NOW AND 00Z ACROSS THE
PANHANDLE, WHICH IS LIKELY TO FALL WITHIN A FEW HOURS' TIME.  EVEN
ALLOWING FOR A HIGH BIAS IN AMOUNTS, THESE AMOUNTS COULD STILL
EXCEED THE FLASH FLOOD GUIDANCE OF 4"/3 HOURS.  THE TIME HORIZON
OF THIS DISCUSSION WAS SET AT SIX HOURS, AS THERE COULD BE FLASH
FLOOD POTENTIAL INTO THE NIGHTTIME HOURS ACROSS NORTHERN FL.

ROTH

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

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

LAT...LON   29778324 29638357 29958390 29928420 29658470 29568530
            29708544 30028565 30288619 30378622 30368586 30548521
            30708465 30888390 30788331 30448305 29888324 29778324