MESOSCALE DISCUSSION 0346
   NWS STORM PREDICTION CENTER NORMAN OK
   1132 AM CDT TUE MAR 31 2009
   
   AREAS AFFECTED...FAR SERN MS INTO SRN AL AND THE FL PNHDL
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 311632Z - 311800Z
   
   THE POTENTIAL FOR SEVERE STORMS CAPABLE OF DAMAGING WINDS...SOME
   HAIL AND PERHAPS A TORNADO OR TWO IS EXPECTED TO INCREASE ACROSS THE
   DISCUSSION AREA THIS AFTERNOON.  CONVECTIVE TRENDS ARE BEING
   MONITORED FOR A POSSIBLE WW.
   
   CLUSTERS OF TSTMS HAVE INCREASED IN BOTH COVERAGE AND INTENSITY OVER
   THE PAST HOUR OR SO FROM FAR SERN LA NEWD/EWD INTO SERN MS...SWRN AL
   AND THE WRN FL PNHDL.  THESE STORMS ARE LIKELY BEING DRIVEN BY
   LOW-LEVEL WAA ALONG 30-40 KT SWLY LLJ WITH THE MAJORITY OF ACTIVITY
   SLIGHTLY ELEVATED TO THE N OF A WARM OR MARINE FRONT WHICH EXTENDED
   FROM S OF PIB TO S OF MOB AS OF 16Z.
   
   CURRENT MOB VWP INDICATES A VERY FAVORABLE VERTICAL SHEAR PROFILE
   FOR SUPERCELLS WITH DEEP-LAYER SHEAR OF 50-60 KT AND CONSIDERABLE
   LOW-LEVEL VEERING WITH 0-1 KM SHEAR OF 35-40 KT.  LATEST MODEL
   GUIDANCE INDICATES THAT THIS STRONG LOW-LEVEL SHEAR WILL TEND TO
   WEAKEN WITH TIME THIS AFTERNOON...THOUGH DEEP-LAYER WIND FIELDS WILL
   REMAIN SUFFICIENTLY STRONG TO SUPPORT UPDRAFT ROTATION.  THE PRIMARY
   QUESTION IS WHETHER SURFACE-BASED STORMS WILL BECOME ESTABLISHED
   SOON ENOUGH TO REALIZE THE STRONG LOW-LEVEL SHEAR CURRENTLY IN
   PLACE.  SHOULD THIS OCCUR...THE POTENTIAL WILL EXIST  FOR A TORNADO
   OR TWO WITH ANY MORE SUSTAINED SUPERCELLS THAT CAN DEVELOP. 
   HOWEVER...SHOULD THE TRANSITION TO MORE SURFACE-BASED STORM
   DEVELOPMENT OCCUR LATER THIS AFTERNOON AS LOW-LEVEL FLOW TEMPORARILY
   RELAXES...THE THREAT FOR TORNADOES SHOULD TEND TO DECREASE. 
   OTHERWISE...EXPECT SOME HAIL AND LOCALLY DAMAGING WIND GUSTS TO
   ACCOMPANY THE MOST INTENSE STORMS.
   
   ..MEAD.. 03/31/2009
   
   
   ATTN...WFO...TAE...MOB...LIX...
   
   LAT...LON   30548916 31058891 31428848 31478763 31328644 31068578
               30548568 30118583 29988712 30018827 30228887 30548916