MESOSCALE DISCUSSION 0173
   NWS STORM PREDICTION CENTER NORMAN OK
   0540 AM CST SAT FEB 28 2009
   
   AREAS AFFECTED...CNTRL/SRN AL
   
   CONCERNING...TORNADO WATCH 40...
   
   VALID 281140Z - 281345Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 40 CONTINUES.
   
   LARGE SCALE ASCENT ALONG SRN PERIPHERY OF THE MID-SOUTH VORT MAX WAS
   BEGINNING TO SPREAD ATOP THE NRN EXTENT OF A LLVL THETA-E RIDGE
   SITUATED ACROSS CNTRL/SRN AL.  TSTMS HAVE INCREASED INVOF THE SFC
   LOW AND CDFNT FROM KBHM SWWD INTO SERN MS...OCCASIONALLY EXHIBITING
   EMBEDDED ROTATION.  IN THE WARM SECTOR...ISOLD DISCRETE CONVECTIVE
   TOWERS HAVE ALSO BEEN DEEPENING...WITH ONE PARTICULAR AND LONG-LIVED
   CELL ACROSS EXTREME SERN MS SHOWING THE MOST ORGANIZATION.  
   
   ALL OF THE WARM SECTOR ACROSS CNTRL/SRN AL...CHARACTERIZED BY
   LOW-MID 60S SFC DEW POINTS... CONTAINS AMPLE LLVL SHEAR FOR A
   TORNADO THREAT...PARTICULARLY WITH THE DISCRETE STORMS THAT BECOME
   ESTABLISHED AHEAD OF THE CDFNT.  OTHERWISE...TSTMS DEVELOPING INVOF
   THE CDFNT WILL POSE RISKS FOR DMGG WIND GUSTS/HAIL...AND PERHAPS AN
   ISOLD EMBEDDED TORNADO.
   
   AS LLVL WARM/MOIST ADVECTION CONTINUES OVER WCNTRL/SWRN GA THROUGH
   THE MORNING COUPLED WITH INCREASING UPR LVL SUPPORT...SVR THREATS
   WILL LIKELY SPREAD EWD.  AS SUCH...WWS MAY BE CONSIDERED FARTHER E
   WITH TIME.
   
   ..RACY.. 02/28/2009
   
   
   ATTN...WFO...FFC...BMX...MOB...JAN...
   
   LAT...LON   31258911 32558801 33058661 32918536 32908493 32348489
               31918521 31798598 31688621 31318668 31258911