MESOSCALE DISCUSSION 2109
   NWS STORM PREDICTION CENTER NORMAN OK
   0141 PM CDT SAT SEP 03 2011
   
   AREAS AFFECTED...SRN AND ERN LA / SRN MS / FAR SWRN AL / WRN FL
   PNHDL
   
   CONCERNING...TORNADO WATCH 828...
   
   VALID 031841Z - 031945Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 828 CONTINUES.
   
   THE THREAT FOR TORNADOES CONTINUES ACROSS THE WATCH AREA.
   
   RECENT RADAR AND SATELLITE IMAGERY SHOW THE CENTER OF T.S. LEE NEAR
   THE LA COAST /INVOF 7R4/ WITH LATEST NHC GUIDANCE INDICATING A
   CONTINUED NWD DRIFT OF SYSTEM THIS AFTERNOON.  OF NOTE IS A
   PRONOUNCED MIDLEVEL DRY SLOT WHICH HAS WRAPPED CYCLONICALLY AROUND
   ERN SEMI-CIRCLE OF T.S...RESULTING IN BREAKS IN THE CLOUDS AND
   RESULTANT POCKETS OF STRONGER DIABATIC HEATING OVER S-CNTRL/SERN LA.
   THIS HEATING COMBINED WITH DEW POINTS IN THE 70S ARE CONTRIBUTING TO
   THE DEVELOPMENT OF MORE ROBUST RAIN BANDS /SOME OF WHICH CONTAIN
   LIGHTNING/ E OF LOW-LEVEL CIRCULATION.  HERE...A VERY MOIST/LOW LCL
   BOUNDARY LAYER WITH MLCAPE OF 500-1000 J/KG IS ALIGNING WITH
   EFFECTIVE SRH OF 200-400 M2/S2.  AS SUCH...EXPECT THE RISK FOR
   SUPERCELLS CAPABLE OF TORNADOES TO CONTINUE ACROSS SAME GENERAL
   AREAS THROUGH THE REMAINDER OF THE DIURNAL HEATING CYCLE.
   
   ..MEAD.. 09/03/2011
   
   
   ATTN...WFO...TAE...MOB...JAN...LIX...LCH...
   
   LAT...LON   30409323 30719253 30979213 31369160 31578861 31528705
               31548650 30828621 30338599 29708638 28998668 28408815
               28469037 28409169 29089282 30409323