MESOSCALE DISCUSSION 0345
   NWS STORM PREDICTION CENTER NORMAN OK
   0858 AM CDT TUE MAR 31 2009
   
   AREAS AFFECTED...PORTIONS OF CNTRL/SRN LA INTO SRN MS
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 311358Z - 311530Z
   
   THE SEVERE WEATHER THREAT IS EXPECTED TO INCREASE THIS MORNING IN
   ASSOCIATION WITH ONGOING MCS.  HAIL AND DAMAGING WINDS WILL BE THE
   PRIMARY THREATS THOUGH A TORNADO OR TWO WILL BE POSSIBLE.
   
   AS OF 1340Z...REGIONAL RADAR IMAGERY INDICATED A QUASI-LINEAR
   CONVECTIVE SYSTEM /QLCS/ EXTENDING FROM JACKSON AND WINN PARISHES IN
   N-CNTRL LA SWWD ST. AUGUSTINE AND SABINE COUNTIES IN SERN TX.  THIS
   SYSTEM IS DISPLAYING SEVERAL EMBEDDED CIRCULATIONS WHILE MOVING EWD
   AT 30-35 KT.  LATEST MESOANALYSIS INDICATES PRIMARY SYNOPTIC COLD
   FRONT FROM CNTRL AR SWWD THROUGH NWRN LA INTO SERN TX.  A RETREATING
   WARM FRONT WAS ANALYZED FROM INTERSECTION WITH COLD FRONT JUST N OF
   TOLEDO BEND BEFORE STRETCHING GENERALLY SEWD THROUGH SERN LA/FAR
   SERN MS AND INTO THE NERN GULF OF MEXICO.
   
   THIS QLCS APPEARS TO BE FOCUSED NEAR THE INTERSECTION OF THE WARM
   AND COLD FRONTS AND DRIVEN LARGELY BY LOW-LEVEL WAA IN ADVANCE OF
   MID-LEVEL VORTICITY MAXIMUM ROTATING EWD THROUGH THE RED RIVER
   VALLEY.  12Z REGIONAL SOUNDINGS INDICATE THAT AIR MASS S OF
   RETREATING WARM FRONT IS RELATIVELY MOIST WITH DEWPOINTS IN THE MID
   60S AND MEAN MIXING RATIOS OF 12-13 G/KG.  WHILE LOW CLOUDS REMAIN
   WIDESPREAD THIS MORNING...THIS MOISTURE COUPLED WITH SOME DIABATIC
   HEATING SHOULD SUPPORT THE DEVELOPMENT OF A MODERATELY UNSTABLE AIR
   MASS ALONG AND S OF WARM FRONT WITH SBCAPE APPROACHING 1000-1500
   J/KG.
   
   CURRENT THINKING IS THAT QLCS WILL CONTINUE EWD ALONG RETREATING
   WARM FRONT TODAY WITH SYSTEM DEVELOPING SWD INTO DESTABILIZING WARM
   SECTOR.  THE COMBINATION OF 45-55 KT OF DEEP-LAYER SHEAR AND
   STRENGTHENING LOW-LEVEL WIND FIELDS WITH EWD EXTENT SHOULD SERVE TO
   MAINTAIN AN ORGANIZED CONVECTIVE SYSTEM WITH EMBEDDED BOWING AND/OR
   SUPERCELL STRUCTURES.  WHILE DAMAGING WINDS AND HAIL WILL BE THE
   PRIMARY SEVERE THREATS...A TORNADO OR TWO WILL BE POSSIBLE...
   ESPECIALLY WITH PORTION OF QLCS INTERACTING WITH WARM FRONT.
   
   ..MEAD.. 03/31/2009
   
   
   ATTN...WFO...MOB...JAN...LIX...LCH...SHV...
   
   LAT...LON   31099345 31459306 31909245 32009166 31929062 31708929
               31408872 30858882 30398958 30219050 30069158 30149253
               30499320 31099345