MESOSCALE DISCUSSION 0450
   NWS STORM PREDICTION CENTER NORMAN OK
   0535 PM CDT THU APR 11 2013
   
   AREAS AFFECTED...PORTIONS SRN AL...WRN FL PANHANDLE.
   
   CONCERNING...TORNADO WATCH 98...
   
   VALID 112235Z - 120030Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 98 CONTINUES.
   
   SUMMARY...TWO PRIMARY BANDS OF STG-SVR TSTMS WILL CONTINUE MOVING
   EWD ACROSS SWRN AL AND WRN FL PANHANDLE...AND MAY MERGE BEFORE
   MOVING OUT OF WW.  DAMAGING GUSTS AND MRGL HAIL ARE PSBL..AS ARE
   TORNADOES FROM EITHER EMBEDDED/QLCS-TYPE CIRCULATIONS OR ANY
   SUPERCELLS THAT CAN DEVELOP.  WW MAY BE CLEARED BEHIND WRN TSTM
   BAND...WHERE LOW-LEVEL CAA AND OUTFLOW WILL COMBINE TO RENDER AIR
   MASS TOO STABLE FOR MAINTENANCE OF SVR THREAT.
   
   DISCUSSION...PRIMARY QLCS STILL WAS EVIDENT AT 2215Z FROM SRN MID TN
   SSWWD ACROSS BHM AND MOB AREAS...SRN AL PORTION SHOWING ABOUT 25 KT
   EWD COMPONENT OF MOTION.  SECONDARY SEGMENT OF TSTMS HAS DEVELOPED
   TO ITS E AND WAS EVIDENT FROM NRN SANTA ROSA COUNTY FL NWD ACROSS
   GZH AREA...MERGING WITH ORIGINAL BAND OVER DALLAS COUNTY AL.  THIS
   MERGER MAY CONTINUE TO OCCUR FROM N/S...OR THAT PART OF INITIAL BAND
   DUE W OF SECONDARY CONVECTION MAY CONTINUE TO WEAKEN IN FAVOR OF ERN
   ACTIVITY.  SFC CHART SHOWS BACKED LOW-LEVEL FLOW AND DEW POINTS
   68-71 F OVER FOREGOING WARM SECTOR...OFFERING FAVORABLE
   STORM-RELATIVE INFLOW WITH RICH THETAE TO ACTIVITY OVER REMAINDER
   WW.  MODIFIED FCST SOUNDINGS SHOW MLCAPE 1000-2000 J/KG...AMIDST
   FIELD OF 45-55 KT EFFECTIVE SHEAR MAGNITUDES.  WITH WEAK
   MLCINH...150-300 J/KG EFFECTIVE SRH...AND INCREASINGLY
   CONFLUENT/CONVERGENT BOUNDARY-LAYER FLOW EXPECTED...THERE ALSO IS
   SOME POTENTIAL FOR SUPERCELLS TO EVOLVE FROM SPOTTY CONVECTION IN
   WARM SECTOR BEFORE BEING SWEPT UP BY QLCS. 
   
   REF SPC MESOSCALE DISCUSSION 448 FOR AREAS OF FL PANHANDLE AND GA E
   OF WW...COVERING THREAT LATER THIS AFTERNOON INTO EVENING FROM BOTH
   QLCS CURRENTLY IN WW AND OTHER ACTIVITY WELL TO ITS E.
   
   ..EDWARDS.. 04/11/2013
   
   
   ATTN...WFO...TAE...BMX...MOB...
   
   LAT...LON   30158835 32098730 31908609 30878625 30398644 30158835