MESOSCALE DISCUSSION 2114
   NWS STORM PREDICTION CENTER NORMAN OK
   1135 PM CDT SAT SEP 03 2011
   
   AREAS AFFECTED...PORTIONS S-CENTRAL/SERN LA...SRN MS...SRN AL...WRN
   FL PANHANDLE.
   
   CONCERNING...TORNADO WATCH 830...
   
   VALID 040435Z - 040630Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 830 CONTINUES.
   
   GIVEN ERRATIC MOVEMENT OF TS LEE AND ONLY MINOR CHANGES IN MESOBETA
   SCALE STRUCTURE OVER MOST FAVORABLE SECTOR...AREA OF PRIMARY TORNADO
   THREAT HAS CHANGED LITTLE DURING PAST SEVERAL HOURS AND SHOULD
   REMAIN ESSENTIALLY OVER WW AREA FOR SEVERAL MORE.
   
   SFC THERMAL AXIS HAS SHIFTED EWD SOMEWHAT...EXTENDING AS OF 04Z FROM
   WSW BTR SEWD ACROSS MSY AND SW PASS AREAS THEN SWD OVER OPEN GULF
   WATERS.  ALTHOUGH NO LONGER BENEFITING THERMALLY FROM DIABATIC SFC
   HEATING...INLAND ADVECTION OF CONVECTIVELY UNDISTURBED MARINE AIR
   NEAR THERMAL AXIS IS MAINTAINING RELATIVELY MAXIMIZED BUOYANCY
   ACROSS SERN LA...WITH MLCAPE 500-1000 J/KG ESTIMATED BASED ON
   MODIFIED LIX RAOB AND RUC SOUNDINGS.  LOW-LEVEL HODOGRAPHS ACTUALLY
   ENLARGE WITH OUTWARD EXTENT FROM CENTER ACROSS SERN LA TOWARD MS/AL
   COASTS.  STRONGEST 0-1 KM AGL SHEAR MAY REMAIN DISPLACED WELL INTO
   PRECIP-INFLUENCED THETAE DEFICIT OVER INLAND SRN PORTIONS MS/AL. 
   TORNADO THREAT ACCORDINGLY MAY BE RELATIVELY MAXIMIZED OVER COASTAL
   AREAS BETWEEN MSY-MOB WHERE NRN FRINGE OF FAVORABLE BUOYANCY
   OVERLAPS SRN PORTION OF STRONGEST SHEAR...THEN SSWWD ACROSS
   CHANDELEUR ISLANDS AND MS RIVER MOUTH REGION.  THIS SWATH ALSO
   SHOULD CONTINUE TO EXHIBIT RELATIVELY DISCRETE CONVECTIVE MODES THAT
   BEST SUPPORT DEVELOPMENT OF POTENTIALLY TORNADIC MINI-SUPERCELLS.
   
   REF NHC ADVISORIES FOR LATEST TRACK/INTENSITY FCST GUIDANCE ON THIS
   CYCLONE.
   
   ..EDWARDS.. 09/04/2011
   
   
   ATTN...WFO...TAE...MOB...JAN...LIX...LCH...SHV...
   
   LAT...LON   30378642 30378687 30218898 30058882 29808882 29558901
               29418926 29158892 28978915 29078927 28778950 29088940
               29328979 29149012 29049071 29109092 29319141 29399121
               29639163 29469177 29589212 29529237 30129263 31389204
               31639119 31758947 31558818 31158670 30628627 30378642