MESOSCALE PRECIPITATION DISCUSSION 0108
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
610 PM EDT FRI APR 01 2016
 
AREAS AFFECTED...CNTRL/ERN GULF COAST INTO SRN GEORGIA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 012209Z - 020345Z
 
SUMMARY...RAINFALL RATES OF 1-2 IN/HR WITH TRAINING OF CONVECTION
AT TIMES CAN BE EXPECTED ACROSS PORTIONS OF THE CNTRL AND ERN GULF
COAST REGION. 3 HR RAIN RATES OF 3-4 INCHES WILL BE POSSIBLE WITH
MAY LEAD TO FLASH FLOODING...ESPECIALLY FOR LOCATIONS THAT
RECEIVED HEAVY RAIN OVER THE PAST 24 HOURS. 

DISCUSSION...21Z SURFACE ANALYSIS PLACED A POSSIBLE SURFACE
LOW...SOUTH OF ERN LOUISIANA...ALONG A COLD FRONT EXTENDING NE TO
SW ACROSS THE SOUTHEAST CONUS. AN OUTFLOW BOUNDARY EXTENDED SWWD
FROM SERN GEORGIA...ACROSS THE CNTRL FLORIDA PANHANDLE AND
INTERSECTED THE FRONT OVER EXTREME SERN LOUISIANA. THE FRONT HAS
BEEN NEARLY STATIONARY OVER THE PAST 3 HOURS TO THE NORTH OF THE
SURFACE LOW...POSSIBLY DUE TO AN ADVANCING UPPER LEVEL TROUGH
TRACKING EAST INTO THE WRN GULF OF MEXICO...SEEN ON WATER VAPOR
IMAGERY. BLENDED TPW IMAGERY SHOWED 2+ INCHES JUST AHEAD OF THE
FRONT IN THE GULF OF MEXICO...CONFIRMED BY A RECENT GPS SITE
PRECIPITABLE WATER OBSERVATION OF 2.05 INCHES ON THE MISSISSIPPI
DELTA. RAP ANALYSES PLACED THE ONLY APPRECIABLE INSTABILITY SOUTH
OF THE OUTFLOW BOUNDARY WHERE VALUES OF 500-1500 J/KG WERE PRESENT.

AS THE UPSTREAM TROUGH CONTINUES EWD ACROSS THE GULF OF
MEXICO...RAP/GFS FORECASTS SHOW THE WEAK SURFACE LOW LOCATED SOUTH
OF ERN LOUISIANA TO SLOWLY EDGE EWD...WITH A RELATIVELY NARROW
CORRIDOR OF STRONGER LOW LEVEL FLOW JUST AHEAD OF THE ADVANCING
COLD FRONT. VAD WIND PROFILE PLOTS ALREADY SHOW 30-40 KTS OF
850-700 MB FLOW WHICH IS EXPECTED TO CONTINUE ALONG THE ERN GULF
COAST OVER THE NEXT SEVERAL HOURS AHEAD OF THE ADVANCING COLD
FRONT...ADVECTING INSTABILITY NORTH ATOP THE OUTFLOW BOUNDARY.
THIS SETUP IS EXPECTED TO PRODUCE CONTINUED CONVECTION ACROSS THE
MPD THREAT AREA WITH RAIN RATES OF 1-2 IN/HR...ESPECIALLY
PROBLEMATIC FOR FLASH FLOODING ACROSS PORTIONS OF SRN ALABAMA
WHICH RECEIVED 4-6 INCHES OF RAIN OVER THE PAST 24 HOURS.

OTTO

ATTN...WFO...FFC...JAX...LIX...MOB...TAE...

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

LAT...LON   31788418 31788233 31028221 30258361 29698554 
            29938738 30168868 30728829 31218749 31468614