MESOSCALE DISCUSSION 0018
   NWS STORM PREDICTION CENTER NORMAN OK
   0943 AM CST TUE JAN 06 2009
   
   AREAS AFFECTED...SERN LA/SERN MS/SRN AL/WRN FL PANHANDLE
   
   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 
   
   VALID 061543Z - 061745Z
   
   A SLOW INCREASE IN CONVECTIVE INTENSITY IS FORECAST OVER THE NEXT
   COUPLE OF HOURS...ALONG WITH A CORRESPONDING INCREASE IN THREAT FOR
   LOCALLY-DAMAGING WINDS/ISOLATED TORNADOES.  TORNADO WATCH WILL
   LIKELY BE REQUIRED IN THE NEXT 1-3 HOURS.
   
   RADAR LOOP DEPICTS A BAND OF SHOWERS AND EMBEDDED THUNDERSTORMS FROM
   SWRN LA NEWD INTO SWRN MS...WITH UPDRAFTS LIKELY ELEVATED JUST TO
   THE COOL SIDE OF A SURFACE BOUNDARY LYING SW-NE ACROSS THIS AREA. 
   THIS BAND OF GENERALLY WEAK CONVECTION CONTINUES ENEWD ACROSS E
   CENTRAL AND SERN MS INTO CENTRAL AL...WITHIN ZONE OF APPARENT WARM
   ADVECTION.
   
   SE OF THIS BAND OF CONVECTION... BREAKS IN THE CLOUD COVER WILL
   CONTINUE TO FACILITATE LIMITED DIURNAL HEATING.  MODIFICATION OF
   MORNING RAOBS TO ACCOUNT FOR THE MOIST/INCREASINGLY-WARM BOUNDARY
   LAYER SUGGEST THE POTENTIAL FOR MIXED-LAYER CAPE IN EXCESS OF 500
   J/KG BY EARLY AFTERNOON.  THIS COMBINED WITH SLOWLY-FALLING
   MID-LEVEL HEIGHTS AFTER MIDDAY SHOULD SUPPORT A GRADUAL INCREASE IN
   CONVECTIVE INTENSITY/LONGEVITY WITH TIME.
   
   THE KINEMATIC ENVIRONMENT REMAINS FAVORABLE FOR ORGANIZED CONVECTION
   ACROSS THIS REGION...WITH BROAD SLY BOUNDARY-LAYER FLOW TOPPED BY
   INCREASINGLY-STRONG/VEERING FLOW WITH HEIGHT.  THIS SUGGESTS
   LOW-LEVEL ROTATION WITHIN LONGER-LIVED UPDRAFTS WILL BECOME MORE
   PREVALENT WITH TIME...ALONG WITH AN ASSOCIATED INCREASE IN THE
   POTENTIAL FOR ISOLATED TORNADOES.  LOCALLY-DAMAGING WINDS WILL ALSO
   BE A POSSIBILITY -- PARTICULARLY LATER AS SOME LINEAR ORGANIZATION
   ALONG THE SURFACE COLD FRONT SEEMS LIKELY.
   
   ..GOSS.. 01/06/2009
   
   
   ATTN...WFO...BMX...MOB...JAN...LIX...LCH...
   
   LAT...LON   29559029 30019132 31069096 32368931 32888797 32188673
               31098644 30078782 29708923 29608967 29559029