MESOSCALE DISCUSSION 0157
   NWS STORM PREDICTION CENTER NORMAN OK
   0157 PM CST TUE FEB 12 2013
   
   AREAS AFFECTED...SRN LA...SRN MS...SRN AL...WRN FL PANHANDLE
   
   CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY 
   
   VALID 121957Z - 122100Z
   
   PROBABILITY OF WATCH ISSUANCE...95 PERCENT
   
   SUMMARY...A THREAT FOR TORNADOES...DMGG WINDS...AND HAIL...IS
   EXPECTED TO INCREASE THIS AFTERNOON ACROSS THE CNTRL GULF COAST IN
   ASSOCIATION WITH A WEAK SFC CYCLONE AND ATTENDANT WARM FRONT. A
   TORNADO WATCH WILL LIKELY BE NEEDED.
   
   DISCUSSION...VISIBLE SATELLITE AND LIGHTNING DATA SHOW CONVECTION
   INCREASING INVOF A WEAK SFC LOW...WHICH WAS CENTERED JUST N OF BPT
   AS OF 19Z. AN ATTENDANT WARM FRONT PARALLEL TO THE GULF COAST IS
   SLOWLY LIFTING NWD ACROSS COASTAL SRN LA...WITH DEWPOINTS OF 65-70 F
   SPREADING INLAND. THE 12Z LCH SOUNDING MODIFIED FOR REPRESENTATIVE
   19Z SFC CONDITIONS SUGGESTS THAT DEVELOPING CONVECTION ALONG/S OF
   THE WARM FRONT WILL LIKELY BE SFC-BASED...WITH SBCAPE VALUES
   APPROACHING 1000 J/KG. MODEST HEIGHT FALLS OVERSPREADING THE AREA IN
   RESPONSE TO AN UPPER TROUGH CENTERED OVER W TX...COMBINED WITH
   FURTHER BOUNDARY LAYER HEATING AND CONVERGENCE ALONG A COLD FRONT
   ATTENDANT TO THE SFC LOW...MAY SUPPORT DEVELOPMENT OF TSTMS THIS
   AFTERNOON THROUGH SRN LA. 
   
   ADDITIONAL SFC-BASED TSTMS MAY DEVELOP INVOF THE WARM FRONT INTO SRN
   MS/AL AND EVENTUALLY THE WRN FL PANHANDLE WITHIN A WEAK WAA
   REGIME...WHERE FAVORABLE HODOGRAPHS/LOW-LEVEL SHEAR PROFILES /PER
   LCH/MOB VWP DATA/ ARE IN PLACE. DEEP-LAYER SHEAR PROFILES ARE
   FAVORABLE FOR ISOLATED SUPERCELLS AND SMALL BOWING SEGMENTS...WITH
   AN ENHANCED TORNADO THREAT ACCOMPANYING DISCRETE STORMS FORMING NEAR
   THE WARM FRONT/SFC LOW. AN ADDITIONAL THREAT OF DMGG WINDS/HAIL MAY
   ALSO ACCOMPANY THE STRONGER STORMS.
   
   ..ROGERS/MEAD.. 02/12/2013
   
   
   ATTN...WFO...TAE...BMX...MOB...JAN...LIX...LCH...
   
   LAT...LON   29089053 29229138 29589312 29709354 30099377 30409370
               30579329 30709193 30899075 31208997 31398928 32028844
               32128678 31898619 31598608 30918584 30518616 30288727
               30278884 29858947 29279018 29089053