MESOSCALE DISCUSSION 0554
   NWS STORM PREDICTION CENTER NORMAN OK
   0900 AM CDT WED APR 24 2013
   
   AREAS AFFECTED...SE LA...SRN MS
   
   CONCERNING...TORNADO WATCH 137...
   
   VALID 241400Z - 241530Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 137 CONTINUES.
   
   SUMMARY...AN ISOLATED SEVERE THREAT WILL CONTINUE ACROSS WW 137 OVER
   THE NEXT FEW HOURS. A BRIEF TORNADO AND WIND DAMAGE SHOULD BE THE
   PRIMARY THREATS. THE THREAT IS EXPECTED TO BECOME INCREASINGLY
   ISOLATED AND WW ISSUANCE IS NOT ANTICIPATED TO THE EAST OF THE
   CURRENT WATCH.
   
   DISCUSSION...THE LATEST SFC ANALYSIS SHOWS A COLD FRONT ADVANCING
   SEWD ACROSS CNTRL MS AND SCNTRL LA WITH A CORRIDOR OF LOW-LEVEL
   MOISTURE EXTENDING NWD ACROSS SE LA INTO SW MS. SFC DEWPOINTS ARE IN
   THE MID TO UPPER 60S F AND OBJECTIVE ANALYSIS SUGGESTS MLCAPE VALUES
   ARE IN TH 500 TO 1000 J/KG RANGE. THE INSTABILITY ALONG WITH
   LARGE-SCALE ASCENT ASSOCIATED WITH A SUBTLE SHORTWAVE TROUGH EVIDENT
   ON WATER VAPOR IMAGERY SHOULD SUPPORT THE CONVECTION FOR SEVERAL
   MORE HOURS THIS MORNING. THE LATEST WSR-88D VWP IN NEW ORLEANS SHOWS
   45 KT OF 0-6 KM SHEAR WITH 0-1 KM SHEAR NEAR 20 KT. THIS WIND SHEAR
   ENVIRONMENT ALONG WITH LCL-HEIGHTS AROUND 500 METERS COULD BE ENOUGH
   FOR A BRIEF TORNADO WITH THE MORE ORGANIZED CELLS. BOWING
   LINE-SEGMENTS COULD ALSO HAVE ISOLATED DAMAGING WIND GUSTS. THE
   THREAT SHOULD BECOME MORE ISOLATED LATER THIS MORNING AS THE CLUSTER
   OF STORMS MOVES EWD INTO WEAKER INSTABILITY.
   
   ..BROYLES/MEAD.. 04/24/2013
   
   
   ATTN...WFO...MOB...JAN...LIX...LCH...
   
   LAT...LON   31619011 30799094 30259191 29859222 29499197 29149122
               29029035 28988970 28808914 29218883 29748887 30358886
               31258906 31619011