MESOSCALE DISCUSSION 0308
   NWS STORM PREDICTION CENTER NORMAN OK
   0647 PM CDT TUE MAR 29 2011
   
   AREAS AFFECTED...SRN LA/SRN MS
   
   CONCERNING...TORNADO WATCH 72...
   
   VALID 292347Z - 300145Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 72 CONTINUES.
   
   A SYNOPTIC BAROCLINIC ZONE IS DRAPED FROM NEAR LCH TO JUST NORTH OF
   BTR TO 25 MILES SSE OF ASD. THIS FEATURE IS LIFTING NWD AS A WARM
   FRONT OVER SERN LA. SFC OBSERVATIONS INDICATE DEWPOINTS IN THE UPPER
   60S AND LOWER 70S SOUTH OF THE FRONT...WHERE 23Z RUC OBJECTIVE
   ANALYSIS INDICATES MLCAPE VALUES AOA 2000 J/KG. THIS FRONT IS
   FORECAST TO BE NUDGED INTO SRN MS DURING THE NEXT FEW HOURS BY
   INCREASING SLY LOW-LEVEL FLOW. SURFACE-BASED CONVECTION IS
   DEVELOPING NEAR AND SOUTH OF THIS WARM FRONT...AND THIS WILL
   CONTINUE TO OCCUR INTO THIS EVENING AS DEEP-LAYER ASCENT INCREASES.
   FARTHER TO THE NORTH...A SECONDARY/MESOSCALE WARM FRONT EXTENDS FROM
   S-CNTRL INTO SERN MS...AND IS FOLLOWED BY DEWPOINTS IN THE LOWER AND
   MIDDLE 60S. BETWEEN THIS FEATURE AND THE SYNOPTIC BOUNDARY...MODEST
   CONVECTIVE INHIBITION FOR A SURFACE-BASED PARCEL WILL RESULT IN A
   CONTINUED POTENTIAL FOR SLIGHTLY ELEVATED CONVECTION. HOWEVER...AS
   THE SYNOPTIC WARM FRONT LIFTS NWD...THIS CONVECTION WILL LIKELY
   BECOME SURFACE BASED.
   
   MODERATE TO STRONG DEEP-LAYER SHEAR /52 KT OF 0-6 KM SHEAR PER VWP
   AT LIX/ IS ALLOWING CONVECTION TO EXHIBIT SUPERCELLULAR
   CHARACTERISTICS...AND THIS WILL LIKELY CONTINUE THROUGH THE EVENING
   HOURS. LOW-LEVEL VERTICAL SHEAR IS FORECAST TO INCREASE DURING THE
   NEXT FEW HOURS...PARTICULARLY INVOF THE SYNOPTIC WARM FRONT...AS A
   LOW-LEVEL JET MATERIALIZES EAST OF A DEEPENING TROUGH EXTENDING FROM
   THE OZARKS TOWARD THE SABINE RIVER VALLEY. THIS IS EXPECTED TO
   RESULT IN AN INCREASING POTENTIAL FOR TORNADOES ACROSS WW72 THROUGH
   THE EVENING HOURS...ESPECIALLY WITH ANY SUPERCELLS. THE CONVECTION
   COULD ALSO GROW UPSCALE INTO ONE OR MORE CONVECTIVE CLUSTERS/LINE
   SEGMENTS...WITH AN ATTENDANT POTENTIAL FOR DMGG WINDS.
   
   ..COHEN.. 03/29/2011
   
   
   ATTN...WFO...MOB...JAN...LIX...LCH...SHV...
   
   LAT...LON   29338969 29159108 29219314 29679373 30649370 31359326
               31779163 31959016 31938863 30598836 29758874 29338969