MESOSCALE DISCUSSION 0304
   NWS STORM PREDICTION CENTER NORMAN OK
   0922 AM CST TUE FEB 26 2008
   
   AREAS AFFECTED...PORTIONS OF CNTRL/SRN GA AND NRN FL
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 78...79...
   
   VALID 261522Z - 261645Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
   78...79...CONTINUES.
   
   THE POTENTIAL FOR LOCALLY DAMAGING WINDS AND LARGE HAIL WILL
   CONTINUE ACROSS WW/S 78 AND 79.  ADDITIONALLY...THE THREAT OF A
   TORNADO OR TWO APPEARS TO BE INCREASING OVER CNTRL/ERN PARTS OF WW
   79.  CONVECTIVE TRENDS ARE BEING MONITORED FOR A POSSIBLE UPGRADE TO
   A TORNADO WATCH OVER NRN FL AND SRN GA.  FINALLY...A DOWNSTREAM WW
   MAY BE REQUIRED BY LATE MORNING E OF WW/S 78/79.
   
   REGIONAL RADAR IMAGERY INDICATES THAT MORE DISCRETE TSTM DEVELOPMENT
   IS EVOLVING AHEAD OF LONG-LIVED QLCS FROM SEMINOLE AND DECATUR
   COUNTIES IN SWRN GA SWWD TO BAY AND GULF COUNTIES IN THE FL PNHDL AS
   OF 1505Z.  MODIFICATION OF 12Z TLH SOUNDING FOR CURRENT SURFACE
   CONDITIONS INDICATES THAT BOUNDARY LAYER HAS WARMED SUFFICIENTLY
   SUCH THAT OBSERVED WARM NOSE IN THE 800-700 MB LAYER IS BECOMING
   LESS INHIBITIVE WITH AIR MASS NOW MODERATELY UNSTABLE WITH MLCAPES
   OF 1000-1500 J/KG.  MOREOVER...LATEST TLH VWP INDICATES THAT
   VERTICAL SHEAR REMAINS QUITE STRONG WITH 0-1 KM SRH OF AROUND 250
   M2/S2 AND 0-6 KM BULK SHEAR OF 60-65 KT.
   
   GIVEN THIS ENVIRONMENT...POTENTIAL FOR SUPERCELLS CAPABLE OF A
   TORNADO OR TWO APPEARS TO BE INCREASING WITH THIS MORE DISCRETE TSTM
   DEVELOPMENT.  CONVECTIVE TRENDS ARE BEING MONITORED FOR A POSSIBLE
   UPGRADE TO A TORNADO WATCH.  LATEST MODEL GUIDANCE DOES SUGGEST THAT
   OBSERVED...STRONG LOW-LEVEL SHEAR WILL BEGIN TO WEAKEN BY THIS
   AFTERNOON.  THEREFORE...THE BETTER TORNADO POTENTIAL WILL LIKELY
   EXIST BEFORE 18Z.
   
   OTHERWISE...EXPECT THAT ONGOING QLCS FROM SW OF AGS TO E OF CEW WILL
   REMAIN CAPABLE OF MAINLY LOCALLY DAMAGING WIND GUSTS.  WHILE 12Z JAX
   AND CHS OBSERVED SOUNDINGS SAMPLED ONLY VERY WEAK CONVECTIVE
   INSTABILITY...DAYTIME HEATING COUPLED WITH THE NEWD FLUX OF AN
   INCREASINGLY MOIST BOUNDARY LAYER SHOULD SUPPORT FAIRLY RAPID AIR
   MASS DESTABILIZATION THIS MORNING...LIKELY MAINTAINING ONGOING MCS
   TOWARD THE ATLANTIC COAST.  GIVEN THE RELATIVELY STRONG WIND
   FIELDS...A SEVERE THREAT WILL LIKELY CONTINUE AND AN ADDITIONAL
   DOWNSTREAM WW MAY BE REQUIRED BY LATE MORNING.
   
   ..MEAD.. 02/26/2008
   
   
   ATTN...WFO...CHS...JAX...FFC...TAE...
   
   30428598 31688497 32488322 32798194 32248121 31288134
   30508155 30038203 29758374 29828532