MESOSCALE PRECIPITATION DISCUSSION 0177
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
912 AM EDT WED MAY 04 2016
 
AREAS AFFECTED...WEST CENTRAL INTO SOUTHEAST FL 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 041320Z - 041720Z
 
SUMMARY...CONVECTION PRODUCING HOURLY RAINFALL RATES NEAR 2 INCHES
WILL CROSS CENTRAL FL THROUGH THE EARLY AFTERNOON HOURS. THE FOCUS
FOR THE HEAVY RAINFALL THREAT COULD BECOME FOCUSED ON THE
DEVELOPING EAST COAST SEA BREEZE TOWARD 18Z.

DISCUSSION...THE CORE OF THE STRONGEST CONVECTION CROSSING WEST
CENTRAL FL CONTINUES TO TRACK EAST AHEAD OF A COLD FRONT CROSSING
NORTH FL. THE CONVECTION IS FOLLOWING THE AXIS OF HIGHEST MOISTURE
(WITH PRECIPITABLE WATER VALUES BETWEEN 1.75 AND 2.00
INCHES...WHICH IS BETWEEN TWO AND THREE STANDARD DEVIATIONS ABOVE
THE MEAN)...AS WELL AS A RIBBON OF 500 TO 1000 J/KG ML CAPE. 

BASED ON THE DUAL POL OUTPUT FROM THE KTBW RADAR...HOURLY RAINFALL
RATES OF 2 INCHES HAS ACCOMPANIED THE CONVECTION DURING ITS SLOW
DRIFT SOUTHWARD. THE WV LOOP SHOWED A SHORT WAVE EMBEDDED IN THE
MID LEVEL WEST SOUTHWEST FLOW...ACTING AS A FOCUS FOR THE CURRENT
CONVECTION. 

THE SHORT WAVE CROSSES THE CENTRAL FL PENINSULA THROUGH THE LATE
MORNING HOURS...AS IT FOLLOWS THE BEST MOISTURE/INSTABILITY AXIS.
THE LATEST HRRR/EXPERIMENTAL HRRR APPEAR TO HAVE THE BEST HANDLE
ON THE LOCATION AND MOVEMENT OF THE CENTRAL FL CONVECTION...AND
EACH MODEL SHOWS THE POTENTIAL FOR AS MUCH AS 3 TO 5 INCHES OF
RAINFALL ACROSS CENTRAL FL THROUGH 17Z. WHILE ONE AND THREE HOUR
FLASH FLOOD GUIDANCE VALUES ARE VERY HIGH...THE POTENTIAL FOR
HOURLY RAINFALL RATES NEAR 2 INCHES...AS WELL AS SHORT TERM
TRAINING AS THE BAND OF CONVECTION DROPS SLOWLY SOUTH...SHOULD
CONSTITUTE A SHORT TERM FLASH FLOOD RISK.

THE NEXT SHORT WAVE IN THE FLOW APPROACHES SOUTHWEST FLOW CLOSER
TO 18Z. AHEAD OF THIS FORCING...CONVECTION IS EXPECTED TO FORM
ALONG THE DEVELOPING EAST COAST SEA BREEZE...IN AN AXIS OF
2000-3000 J/KG AND INCREASINGLY DEEP MOISTURE. THE THREAT FOR
HEAVY RAINFALL/LOCALIZED FLASH FLOODING COULD BECOME FOCUSED ON
THE SEA BREEZE ACTIVITY...ESPECIALLY CLOSER TO 18Z.

HAYES

ATTN...WFO...MFL...MLB...TBW...

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

LAT...LON   28198073 28078045 27158001 26717996 25827984 
            25408012 25448042 25668060 25918066 26058071 
            26458078 26458150 26368203 26558246 26678248 
            27388275 27758248 27978188 28128111