MESOSCALE DISCUSSION 2126
   NWS STORM PREDICTION CENTER NORMAN OK
   0629 PM CDT SUN SEP 04 2011
   
   AREAS AFFECTED...PORTIONS SERN LA...CENTRAL/SRN MS...CENTRAL/SRN
   AL...SWRN GA...PANHANDLE AND COASTAL-BEND REGIONS OF FL.
   
   CONCERNING...TORNADO WATCH 833...836...
   
   VALID 042329Z - 050130Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 833...836...CONTINUES.
   
   WWS ARE LIKELY TO BE REPLACED/CONSOLIDATED DURING 02Z-03Z TIME
   FRAME...BEFORE THEIR SCHEDULED 03Z EXPIRATION.
   
   MOST FAVORABLE JUXTAPOSITION OF LOW-LEVEL SHEAR AND AT LEAST MRGL
   BUOYANCY THROUGH EARLY EVENING WILL REMAIN OVER SWATH BOUNDED
   ROUGHLY BY PTN-MCB-MEI-VPS.  VWP AND FCST SOUNDINGS INDICATE 0-1 KM
   SH 200-300 J/KG ACROSS MUCH OF THIS AREA...LOCALLY HIGHER.  THOUGH
   VIS IMAGERY SHOWS CLOUD BREAKS ARE CLOSING OVER MUCH OF THIS REGION
   ATTM...EARLIER SFC DIABATIC HEATING AND CYCLONICALLY CURVED NWD
   ADVECTION OF THAT AIR HAS RESULTED IN SFC TEMPS MID-UPPER 70S WITH
   ISOLATED NEAR 80 F...OFFSETTING WEAK LAPSE RATES ENOUGH TO YIELD
   ESTIMATED MLCAPE IN 200-500 J/KG RANGE NEAR I-20 AND 500-1000 J/KG
   NEAR COAST.  FAVORABLE THETAE WILL CONTINUE TO BE ADVECTED NWD FROM
   GULF OVER THOSE AREAS THAT ARE RELATIVELY DEVOID OF SUSTAINED
   PRECIP...WITH AIR MASS RECOVERY ALSO FAVORED BEHIND DEPARTING PRECIP
   AREAS.  0-3 KM CAPE IN SUPPORT OF SUSTAINED SFC-BASED UPDRAFT
   DEVELOPMENT DROPS OFF MARKEDLY N OF ABOUT A GZH-PIB-MCB LINE.  SFC
   DIABATIC COOLING WILL BE SLOW TO OCCUR...WITH MODIFIED FCST
   SOUNDINGS SUGGESTING THAT EFFECTIVE SFC-BASED LIFTED PARCELS WILL BE
   MAINTAINED WELL PAST 03Z WW EXPIRATION TIME OVER MUCH OF THIS AREA. 
   
   FARTHER E ACROSS CENTRAL-ERN FL PANHANDLE -- PRIMARILY WW 833
   COVERAGE AREA -- TORNADO POTENTIAL IS MORE ISOLATED/CONDITIONAL. 
   TLH VWP HAS BEEN ALTERED AND MADE SOMEWHAT UNREPRESENTATIVE OF
   AMBIENT KINEMATIC ENVIRONMENT BY RECENT PASSAGE OF OUTFLOW-DOMINANT
   CONVECTION...WHICH ALSO HAS SUBSTANTIALLY REDUCED INSTABILITY
   INLAND.  MODIFIED VWP AND FCST SOUNDINGS INDICATE HODOGRAPH
   ALIGNMENT SUCH THAT SRH IS MAXIMIZED FOR CONSIDERABLE RIGHTWARD/EWD
   DEVIANCE OF CELL-MOTION VECTOR...AND ALSO...WEAKER 0-1 KM AGL SHEAR
   VECTORS THAN FARTHER W ACROSS MUCH OF WW 836.  HOWEVER...AIR MASS
   RECOVERY IS POSSIBLE INVOF COAST...SUPPORTING POTENTIAL FOR ANY
   MINI-SUPERCELLS OVER GULF TO MOVE ASHORE.
   
   REF NHC ADVISORIES FOR LATEST TRACK/INTENSITY FCST GUIDANCE ON THIS
   CYCLONE.
   
   ..EDWARDS.. 09/04/2011
   
   
   ATTN...WFO...TBW...JAX...TAE...BMX...MOB...JAN...LIX...
   
   LAT...LON   29249133 30379037 31429047 31879105 32778937 32778694
               31418429 30178320 29638297 29248312 29898366 30078417
               29908442 29558501 29688538 29948545 30408631 30308744
               30198807 30228899 30148914 30048883 29818880 29498909
               29398925 29178895 28988916 29058926 28808948 29098936
               29308978 29059019 29119085 29249133