ZCZC SPCSWOMCD ALL
ACUS11 KWNS 201703 
SPC MCD 201703 
NCZ000-SCZ000-GAZ000-201800-

MESOSCALE DISCUSSION 0396
NWS STORM PREDICTION CENTER NORMAN OK
1203 PM CDT MON APR 20 2015

AREAS AFFECTED...FAR NE GA...UPSTATE SC...PORTIONS OF WRN AND
CENTRAL NC

CONCERNING...SEVERE POTENTIAL...WATCH NEEDED SOON 

VALID 201703Z - 201800Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...SCATTERED STRONG TO SEVERE THUNDERSTORMS ARE EXPECTED TO
DEVELOP ACROSS PORTIONS OF UPSTATE SC INTO WESTERN AND CENTRAL NC.
HAIL AND STRONG WINDS WILL BE THE MAIN THREAT BUT A TORNADO CAN NOT
BE RULED OUT. A WATCH WILL LIKELY BE NEED SOON.

DISCUSSION...ISOLATED THUNDERSTORMS WERE DEVELOPING OVER NORTHEAST
GA AHEAD OF THE SURFACE COLD FRONT. WHILE INITIAL STORMS MAY PRODUCE
SOME GUSTY WINDS OR SMALL HAIL...THE GREATER THREAT FOR SEVERE
WEATHER WILL BE FURTHER DOWNSTREAM ACROSS PARTS OF UPSTATE SC INTO
WESTERN AND CENTRAL NC. HERE...TEMPERATURES HAVE WARMED INTO THE 70S
WITH SOME AREAS NEAR 80 DEGREES EARLY THIS AFTERNOON. WHILE SOME
HIGH CLOUDS ARE MOVING OVER THE REGION...SUFFICIENT INSTABILITY
EXISTS WITH MESOANALYSIS INDICATING A NEARLY UNCAPPED ENVIRONMENT.
AS EVIDENCE OF THIS...CU DEVELOPMENT WAS NOTED IN LATEST VIS
SATELLITE IMAGERY FROM NEAR THE SC/NC BORDER INTO CENTRAL NC. STRONG
DEEP LAYER SHEAR WILL SUPPORT SUPERCELL STRUCTURES THAT COULD REMAIN
SEMI-DISCRETE. MODEST MIDLEVEL LAPSE RATES AND COOL TEMPERATURES
ALOFT /-14 DEG C AT 500 MB PER GSO 12Z RAOB/ WILL SUPPORT SEVERE
HAIL. FAST STORM MOTION AND DCAPE NEAR 1000 J/KG ALSO WILL SUPPORT
STRONG/LOCALLY DAMAGING WIND GUSTS. WHILE THE TORNADO THREAT IS
EXPECTED TO REMAIN LOW...HI-RES GUIDANCE SUGGESTS SOME BACKING OF
LOW-LEVEL WINDS IS POSSIBLE AS A WEAK SURFACE TROUGH DEVELOPS AHEAD
OF THE COLD FRONT ACROSS CENTRAL NC INTO N-CENTRAL SC. A BRIEF
TORNADO CANNOT BE RULED OUT IF THIS OCCURS.

..LEITMAN/HART.. 04/20/2015

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...RAH...ILM...RNK...CAE...GSP...MRX...FFC...

LAT...LON   34308032 34038128 33878191 33818215 33838304 33978366
            34218407 34408408 34718385 35308321 35838237 36088158
            36028061 35787990 35397945 35037938 34677960 34308032 

NNNN