MESOSCALE PRECIPITATION DISCUSSION 0257
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1258 PM EDT FRI AUG 08 2014
 
AREAS AFFECTED...WESTERN/CENTRAL TN...FAR NORTHERN MS...EXTREME
NRN AL 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 081645Z - 082100Z
 
SUMMARY...BACK-BUILDING/REPEATING CONVECTION AND VERY INTENSE
RAINFALL RATES WILL FOSTER SOME FLASH FLOOD CONCERNS THE NEXT FEW
HOURS.

DISCUSSION...THE LATEST SAT IMAGERY SHOWS A GRADUALLY ORGANIZING
BAND OF STRONGER COLD-TOPPED CONVECTION OVER WRN TN THAT IS MOVING
SLOWLY EASTWARD. MEANWHILE...THE VIS IMAGERY IS INDICATING A
GRADUALLY EXPANDING CU/TCU FIELD OVER NERN AR AND WRN TN ADJACENT
THE AREAS OF ONGOING CONVECTION WHICH INDICATES A TREND TOWARD
ADDITIONAL INSTABILITY ACROSS THE REGION.

IN FACT...THE LATEST RAP ANALYSIS SHOWS A POOL OF VERY UNSTABLE
AIR NOW OVER NRN MS AND SWRN TN...WITH SBCAPE VALUES APPROACHING
4000 J/KG. THIS ENERGY AHEAD OF THE ONGOING CONVECTION COUPLED
WITH SHORTWAVE ENERGY OVER SRN IL/NRN AR AND WRN KY THAT IS
DIGGING ESEWD SHOULD HELP TO ORGANIZE AND EXPAND CONVECTION
FURTHER.

THE CONVECTION WILL BE MOVING OVER AREAS THAT HAVE SEEN HVY
RAINFALL AMOUNTS OVER THE LAST 24 HRS...AND ESP OVER WRN/CNTRL TN.
MEANWHILE...THE PWAT ENVIRONMENT IS VERY MOIST WITH GOES-SOUNDER
PWATS NEAR OR SLIGHTLY OVER 2 INCHES. THIS SHOULD SUPPORT RAINFALL
RATES OF 2 TO 3 INCHES/HR...AND GIVEN WET SOIL CONDITIONS
LOCALLY...FLASH FLOODING WILL BE POSSIBLE.

ORRISON

ATTN...WFO...OHX...HUN...MEG...

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

LAT...LON   36128869 36408782 36378695 36238619 35698591 35148635
            34818723 34568885 34539002 34889035 35389002 35828929
            36128869