MESOSCALE PRECIPITATION DISCUSSION 0697
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
720 AM EST FRI DEC 25 2015
 
AREAS AFFECTED...FAR SOUTHEAST AR...NORTHERN MS...NORTHERN
AL...SOUTH CENTRAL TO SOUTHEAST TN INTO FAR NW GA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 251218Z - 251618Z
 
SUMMARY...CONVECTION CONTINUES TO TRAIN IN A SOUTHWEST TO
NORTHEASTERLY DIRECTION OVER PORTIONS OF THE LOWER MS VALLY INTO
THE TN VALLEY.  TRAINING POTENTIAL LIKELY TO CONTINUE THROUGH THIS
MORNING..RESULTING IN FLASH FLOODING.

DISCUSSION...CLOUD TOPS CONTINUE TO COOL AS PER LATEST SATELLITE
IMAGERY WITH THE ENHANCING CONVECTION TO THE SOUTHEAST OF THE
FRONTAL BOUNDARY EXPECTED TO REMAIN STATIONARY ACROSS FAR
SOUTHEAST AR...INTO WESTERN TN.  PW VALUES REMAIN MUCH ABOVE
AVERAGE IN MOIST SOUTHWESTERLY LOW LEVEL FLOW TO THE SOUTHEAST OF
THIS FRONT WITH VALUES 2 TO 3+ STANDARD DEVIATIONS ABOVE THE MEAN.
 

LITTLE CHANGE IN THE OVERALL PATTERN EXPECTED THROUGH THIS MORNING
WITH DEEP LAYERED SOUTHWESTERLY FLOW REMAINING PARALLEL TO THE
CURRENT AREA OF CONVECTION.  THE LATEST HI RES GUIDANCE IS SHOWING
THE POTENTIAL FOR TRAINING...ALTHOUGH FORECASTS VERIFYING THIS
MORNING SEEM TO ALREADY BE TOO SLOW TO PUSH HEAVY PRECIPITATION
DOWNSTREAM. QPF FORECASTS FROM THESE HI RES MODELS DO SHOW THIS
TRAINING POTENTIAL CONTINUING THROUGH THIS MORNING...ALBEIT NOR
NECESSARILY IN AREAS CURRENT ACTIVITY WOULD SUGGEST.  THE HI RES
ARW AND THE 27 KM GFS OUTPUT SEEM TO HAVE THE BEST HANDLE ON THE
CURRENT ACTIVITY..BOTH DEPICTING THE POTENTIAL FOR HEAVY TO
LOCALLY EXCESSIVE RAINS STREAKING DOWNSTREAM ACROSS NORTHERN
MS..NORTHERN AL...SOUTHEAST TN INTO FAR NW GA.  THE 1100 UTC HRR
SEEMS DEFICIENT WITH CONVECTION ACROSS THESE AREAS...FOCUSING ITS
AXIS SEEMINGLY TOO FAR TO THE NORTH.

IN AREAS OF TRAINING..1 TO 2+ INCH RAINFALL AMOUNTS IN AN HOUR AND
TOTALS OVER 5 INCHES POSSIBLE.

ORAVEC

ATTN...WFO...BMX...FFC...HUN...JAN...LZK...MEG...MRX...OHX...
SHV...

ATTN...RFC...LMRFC...OHRFC...SERFC...

LAT...LON   35798576 35568445 35398430 34598457 34328494 
            33648654 33428783 32749026 32349151 32369202 
            32369205 32709263 33569159 34908852 35468704