MESOSCALE DISCUSSION 0237
   NWS STORM PREDICTION CENTER NORMAN OK
   1038 AM CST TUE FEB 26 2013
   
   AREAS AFFECTED...PARTS OF ERN/SERN SC...ERN/SERN GA...AND NERN
   THROUGH CENTRAL FL
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 261638Z - 261745Z
   
   PROBABILITY OF WATCH ISSUANCE...60 PERCENT
   
   SUMMARY...A NEW TORNADO WATCH IS BEING CONSIDERED TO THE N THROUGH
   NE OF WW 46 FOR PARTS OF SERN/ERN GA INTO SRN/ERN SC.
   MEANWHILE...THE ENVIRONMENT EXTENDING SWD INTO NERN TO CENTRAL FL
   REMAINS CONDUCIVE FOR A TORNADO THREAT AND POTENTIAL FOR DAMAGING
   WINDS.
   
   DISCUSSION...OBSERVATIONAL DATA THIS MORNING INDICATED THE WARM
   FRONT EXTENDING ENEWD FROM A TRIPLE POINT LOW LOCATED OVER CENTRAL
   GA /20 SE MCN/ HAD MOVED INLAND OVER SERN GA /W OF SAV/ AND ACROSS
   SRN AND CENTRAL PORTIONS OF THE SC COAST.  BREAKS IN THE CLOUDS HAVE
   DEVELOPED INTO SRN SC /GENERALLY TO THE S-SW OF CHS/ ALLOWING FOR
   SURFACE HEATING. MODIFIED 12Z CHS SOUNDING WITH CURRENT SURFACE
   TEMPERATURE/DEWPOINT SHOWS INHIBITION HAS WEAKENED AND IS CLOSER TO
   SUPPORTING SURFACE-BASED STORMS. THIS COMBINED WITH MOISTURE
   ADVECTION IS AIDING IN ONGOING DESTABILIZATION WITH MUCAPE UP TO AT
   LEAST 500 J/KG OVER SRN-SERN GA IN THE WAKE OF THE EARLIER
   CONVECTION THAT HAS MOVED TO AND OFF THE GA COAST.  STRONG ASCENT
   LOCATED WITHIN THE EXIT REGION OF A 140 KT UPPER LEVEL JET IS
   EVIDENT GIVEN THE TRANSVERSE CONVECTIVE BANDS SPREADING FROM THE NRN
   GULF OF MEXICO INTO SWRN GA AT THIS TIME PER VISIBLE SATELLITE
   IMAGERY.  THIS ASCENT COMBINED WITH CONVERGENCE INVOF THE TRIPLE
   POINT...WARM FRONT AND SWD EXTENDING COLD FRONT IS SUPPORTING RECENT
   LOWER TROPOSPHERE CONVECTIVE CLOUDS ADVANCING INTO SERN GA.  FURTHER
   SURFACE HEATING ACROSS SERN GA INTO SRN AND EVENTUALLY ERN SC AND
   THE NEWD SPREADING DEEP LAYER ASCENT SHOULD PROVE FAVORABLE FOR NEW
   TSTM DEVELOPMENT INTO THE AFTERNOON.  ALTHOUGH INSTABILITY MAY
   REMAIN MARGINAL... STRONG SHEAR IN PLACE IS SUPPORTIVE FOR ORGANIZED
   SEVERE STORMS /SUPERCELLS AND BOWING SEGMENTS/.  CHS WSR-88D VWP
   DATA INDICATED LOW LEVEL SHEAR ALREADY MORE THAN ADEQUATE FOR A
   TORNADO THREAT TODAY WITH 0-1 KM SRH AROUND 300 M2/S2 AND SFC-1 KM
   SHEAR NEAR 40 KT.  
   
   ...DISCUSSION FOR WW 46...
   AT 16Z...REGIONAL RADAR IMAGERY SHOWED CONVECTION WITH EMBEDDED
   LIGHTNING STRIKES EXTENDING FROM NERN THROUGH CENTRAL TO WEST
   CENTRAL FL. DESPITE CLOUDINESS/PRECIPITATION EXTENDING EWD OF THE
   APPARENT STRONGER BAND OF CONVECTION /NEAR AND E OF SGJ TO THE
   TAMPA-ST PETERSBURG-SARASOTA METRO AREAS/...THE PRESENCE OF STRONG
   LOW LEVEL AND DEEP LAYER SHEAR WITH MODERATE INSTABILITY WILL
   CONTINUE TO SUPPORT DAMAGING WINDS AND A TORNADO THREAT.  
   
   ALTHOUGH CONVECTION HAS MOVED E OF THE NRN EXTENT OF WW 46 ACROSS
   SERN GA AND FAR NERN FL...PARTS OF THIS WATCH IN SERN GA WOULD BE
   INCLUDED IN ANY NEW WATCH ISSUED.  REFER TO DETAILS INCLUDED IN
   DISCUSSION ABOVE FOR THE NEW WATCH POTENTIAL.
   
   ..PETERS/CORFIDI.. 02/26/2013
   
   
   ATTN...WFO...ILM...CHS...CAE...MFL...MLB...TBW...JAX...FFC...
   
   LAT...LON   27348305 28238317 28778294 29008264 29558216 31488191
               32188249 33118199 33807991 32947906 31718050 31058090
               29508069 28838022 28608074 27648089 27458091 27198098
               26838191 26818268 27348305