MESOSCALE PRECIPITATION DISCUSSION 0436
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
449 PM EST TUE DEC 23 2014
 
AREAS AFFECTED...WESTERN FL...SOUTHERN GA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 232145Z - 240245Z
 
SUMMARY...PERSISTENT AND REPEATING CLUSTERS OF VERY HEAVY SHOWERS
AND THUNDERSTORMS MAY RESULT IN SOME FLASH FLOODING THROUGH THE
EVENING.

DISCUSSION...THE LATEST IR SAT IMAGERY SHOWS VERY COLD-TOPPED
CONVECTION OVER PORTIONS OF THE FL PANHANDLE AND ESPECIALLY
FURTHER SOUTH OUT OVER THE NORTHERN GULF OF MEXICO. ALL OF THE
ACTIVITY IS FOCUSED WITHIN A STRONG WARM ADVECTION PATTERN WITH
NEARLY 50 KTS OF LOW LEVEL JET ENERGY INTERACTING WITH A FRONTAL
ZONE LIFTING SLOWLY NORTH ACROSS THE EASTERN GULF COAST STATES.
ALL THE WHILE...A SHORTWAVE TROUGH APPROACHING THE LOWER MS VALLEY
IS FOSTERING INCREASINGLY STRONG LARGE SCALE ASCENT.

OVER THE NEXT FEW HOURS...THE ONGOING CONVECTION MAY TEND TO
INCREASE IN COVERAGE AND INTENSITY OWING TO THE APPROACH OF THE
AFOREMENTIONED SHORTWAVE...BUT ALSO TO INCREASINGLY STRONG
MOISTURE TRANSPORT. THE LATEST SREF MEAN MOISTURE FLUX ANOMALIES
IN THE 850MB TO 700MB LAYER ARE FORECAST TO INCREASE TO OVER 4 STD
DEV ABOVE NORMAL BY 00Z WHICH WILL DRIVE THE POTENTIAL FOR EVEN
HEAVIER RAINFALL RATES THAN WHAT HAS BEEN ALREADY OBSERVED TODAY.
THE PERSISTENT AND EXPECTED CONCENTRATED NATURE OF THE CONVECTION
WILL LIKELY FAVOR SHORT-TERM CONCERNS FOR SOME FLASH
FLOODING...ESPECIALLY WHERE EARLIER RAINS HAVE SATURATED THE
GROUND.

THE 12Z ARW AND 12Z NMMB APPEAR TO GENERALLY HAVE THE BEST HANDLE
ON THE ONGOING CONVECTION INVOLVING THE FL PANHANDLE...AND SUGGEST
THE POTENTIAL FOR 2 TO 4 INCHES OF ADDITIONAL RAIN WITH ISOLATED
HEAVIER AMOUNTS THROUGH THE MID-EVENING HOURS. WILL CONTINUE TO
MONITOR.

ORRISON

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

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

LAT...LON   31578315 31118229 30298302 29478504 29738567 
            30238570 30828494