MESOSCALE DISCUSSION 0764
   NWS STORM PREDICTION CENTER NORMAN OK
   0324 PM CDT FRI MAY 08 2009
   
   AREAS AFFECTED...CNTRL AND NERN AR THROUGH WRN TN
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 267...
   
   VALID 082024Z - 082130Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 267
   CONTINUES.
   
   NEW WW WILL BE NEEDED TO REPLACE WW 267 WHICH IS SCHEDULED TO EXPIRE
   AT 21Z. A TORNADO WATCH WILL BE ISSUED SOON FOR A PORTION OF MIDDLE
   AND WRN TN TO REPLACE A PORTION OF SEVERE THUNDERSTORM WATCH 268.
   
   TRAILING END OF CONVECTIVE OUTFLOW BOUNDARY EXTENDS ACROSS NWRN TN
   THROUGH NRN AR. OVERALL TREND HAS BEEN FOR STORMS TO UNDERGO A
   TEMPORARY WEAKENING DURING THE LAST COUPLE HOURS...BUT A COUPLE OF
   STRONG STORMS REMAIN ACROSS NERN AR. THE BOUNDARY LAYER SOUTH OF THE
   OUTFLOW BOUNDARY IS MODERATELY UNSTABLE...BUT STILL APPEARS CAPPED
   TO SURFACE BASED STORMS. HOWEVER...THE 18Z RAOB FROM LITTLE ROCK
   INDICATED THE ORIGINAL CAPPING LAYER HAS UNDERGONE LIFTING AND
   MOISTENING. TENDENCY WILL BE FOR THE LOW LEVEL JET TO SHIFT NEWD
   THROUGH THE TN AND OH VALLEY. CURRENT THINKING IS THAT ADDITIONAL
   STORMS MAY DEVELOP FARTHER EAST THROUGH WRN INTO MIDDLE TN WHERE CAP
   IS WEAKER AND SHEAR PROFILES ARE SUFFICIENT FOR SUPERCELLS AND
   ISOLATED TORNADOES.
   
   ..DIAL.. 05/08/2009
   
   
   ATTN...WFO...MRX...OHX...MEG...
   
   LAT...LON   36139057 36088884 36588450 35458513 35328894 35469042
               36139057