MESOSCALE DISCUSSION 0663
   NWS STORM PREDICTION CENTER NORMAN OK
   0538 PM CDT THU MAY 16 2013
   
   AREAS AFFECTED...NORTH-CENTRAL/NORTHEAST LA AND FAR SOUTHWEST MS
   
   CONCERNING...TORNADO WATCH 164...
   
   VALID 162238Z - 170015Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 164 CONTINUES.
   
   SUMMARY...LARGE HAIL/DAMAGING WIND AND SOME TORNADO POTENTIAL WILL
   CONTINUE ESPECIALLY WITH A SOUTHEASTWARD-MOVING SUPERCELL ACROSS
   NORTH-CENTRAL/NORTHEAST LA. TORNADO WATCH 164 CONTINUES UNTIL 01Z.
   MONITORING TRENDS FOR A NEW WATCH TO THE EAST-SOUTHEAST OF WW
   164...POTENTIALLY INCLUDING ADDITIONAL PORTIONS OF LA/FAR SOUTHWEST
   MS.
   
   DISCUSSION...A SUPERCELL ACROSS NORTH-CENTRAL LA CONTINUES TO MOVE
   SOUTHEASTWARD AND ROUGHLY PARALLEL I-49 TO THE NORTHEAST...NEARING
   THE WINNFIELD LA VICINITY AS OF 2230Z. THIS SUPERCELL WILL LIKELY
   CONTINUE TO SPREAD EAST-SOUTHEASTWARD ACROSS THE MOIST/INSTABILITY
   AXIS ACROSS NORTH-CENTRAL LA IN THE SHORT-TERM...WHERE SURFACE
   DEWPOINTS ARE IN THE MIDDLE 60S F AND MLCAPE IS ESTIMATED TO BE
   AROUND 1250-1500 J/KG. 
   
   LARGE HAIL WILL LIKELY REMAIN THE MOST COMMON RISK THROUGH THE
   23Z-00Z TIME FRAME. HOWEVER...SOME TORNADO POTENTIAL WILL CONTINUE
   AS WELL. WSR-88D VWP DATA FROM FORT POLK INDICATES AS MUCH AS 80-100
   M2/S2 OF 0-1 KM SRH...ALTHOUGH STRONGER /30-45 KT/ SOUTHWESTERLIES
   ARE NOTED JUST ABOVE THAT WITHIN THE 2-3 KM LAYER. GIVEN THAT THIS
   SUPERCELL MAY BEGIN TO MOVE OUTSIDE THE WATCH AFTER 00Z...CURRENT
   TRENDS WILL CONTINUE TO BE MONITORED FOR THE POSSIBILITY OF A NEW
   WATCH TO THE EAST-SOUTHEAST OF TORNADO WATCH 164...INCLUDING
   ADDITIONAL PORTIONS OF LA/FAR SOUTHWEST MS.
   
   OTHERWISE...A TREND TOWARD SUBSIDENCE ALOFT IN THE IMMEDIATE WAKE OF
   THE UPPER LOW PUTS ADDITIONAL DEVELOPMENT ACROSS THE ARKLATEX A BIT
   INTO QUESTION. HOWEVER...SUFFICIENT CONVERGENCE/WEAK CAPPING ALOFT
   SUGGESTS THAT SOME ADDITIONAL DEVELOPMENT CANNOT BE ENTIRELY RULED
   OUT OVER THE NEXT HOUR OR TWO.
   
   ..GUYER.. 05/16/2013
   
   
   ATTN...WFO...JAN...LIX...LCH...SHV...
   
   LAT...LON   32829395 32289266 31919153 31499115 30919140 30839192
               31619337 32829395