MESOSCALE PRECIPITATION DISCUSSION 0080
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1245 AM EDT THU MAY 29 2014
 
AREAS AFFECTED...SOUTHERN AND SOUTHEASTERN LA/SOUTHERN MS/SOUTHERN
AL/FL PANHANDLE... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 290444Z - 290914Z
 
SUMMARY...THERE IS INCREASING CONFIDENCE IN HEAVY RAINFALL ALONG
THE CENTRAL GULF COAST WHICH MAY LEAD TO AREAS OF FLASH FLOODING.
IT MAY TAKE A FEW HOURS OF PERSISTENT HIGH RAINFALL RATES GIVEN
MUCH OF THE REGION ENCOMPASSED BY THE MPD CONTAINS FAIRLY HIGH FFG
VALUES. 

DISCUSSION...THE PAST FEW IMAGES FROM THE IR SATELLITE IMAGERY
SHOWED CLOUD TOPS RAPIDLY COOLING...PARTICULARLY ALONG THE
IMMEDIATE GULF COAST WHERE SURFACE CONVERGENCE HAS BEEN MAXIMIZED.
00Z RAOBS ACROSS THE REGION INDICATED AN ATMOSPHERE NEAR
SATURATION FROM THE BOUNDARY LAYER UP TO THE UPPER TROPOSPHERE
WITH PWATS AROUND 2 INCHES. THE 03Z RAP SHOWED LOW-LEVEL WINDS
GRADUALLY BACKING FROM THE SSW MORE TOWARD THE SSE OVERNIGHT WHICH
MAINTAINS A STEADY FLUX OF MOISTURE TOWARD SOUTHEASTERN LA. RADAR
AND SATELLITE IMAGERY SUGGESTED CONTINUAL REGENERATION OF
CONVECTION ALONG THE LEADING EDGE OF THE LOW-LEVEL INFLOW ACROSS
THE SOUTH-CENTRAL LA COAST. THE 1000 TO 2000 J/KG OF MLCAPE
CONFINED TO THE COASTLINE SOUTHWARD INTO THE NORTHERN GULF OF
MEXICO SHOULD HELP MAINTAIN LOCAL UPDRAFTS WITHIN THE MOIST AND
UNSTABLE ENVIRONMENT. NOT QUITE AS CONCERNED WITH ACTIVITY FURTHER
INLAND GIVEN THE COASTAL CONVECTION HAS ROBBED MUCH OF THE
MOISTURE CONTENT FROM LOCATIONS FARTHER NORTH. LOCAL METARS ACROSS
THE REGION HAVE REPORTED 1 TO 2 INCHES OF RAINFALL IN THE PAST 3
HOURS. EXPECT SUCH RATES TO CONTINUE AS THE CONVECTION PERSISTS
THE NEXT SEVERAL HOURS. THERE ARE INDICATIONS FROM THE NEW 00Z
HIGH-RESOLUTION GUIDANCE THAT SOME OF THE ACTIVITY MAY SHIFT
FURTHER WEST ALONG THE LA COAST. THIS SEEMS REASONABLE GIVEN THE
LATEST IR SATELLITE TRENDS.


RUBIN-OSTER

ATTN...WFO...MOB...JAN...LIX...LCH...

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

LAT...LON   29589171 30399034 31188930 31398838 31328761 30818703
            30288713 29998795 29508864 28608966 28409116 29589171