MESOSCALE DISCUSSION 1735
   NWS STORM PREDICTION CENTER NORMAN OK
   0436 AM CDT SUN AUG 18 2013

   AREAS AFFECTED...WRN FL PANHANDLE...SWRN AL

   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

   VALID 180936Z - 181130Z

   PROBABILITY OF WATCH ISSUANCE...20 PERCENT

   SUMMARY...ROTATING STORMS OFF THE GULF COAST MAY PRODUCE A BRIEF
   TORNADO OR LOCALIZED DAMAGING WINDS AS THEY MOVE ASHORE THIS
   MORNING. BUT WITH A SUBSTANTIAL DECREASE IN INSTABILITY WITH INLAND
   EXTENT...THIS THREAT SHOULD REMAIN TOO MARGINAL TO WARRANT A WW
   ISSUANCE.

   DISCUSSION...09Z SURFACE ANALYSIS PLACED A 1012 MB CYCLONE NEAR THE
   MOUTH OF THE MS RIVER WITH A SLOW-MOVING WARM FRONT EXTENDING EWD TO
   JUST OF N OF AAF. A PERSISTENT STORM CLUSTER WITH REGENERATIVE
   UPDRAFTS HAS BEEN SUSTAINED IN THE WARM SECTOR OFF THE COAST TO THE
   S/SW OF THE MOB/PNS AREA. A LONGER-LIVED ROTATING CELL HAD BEEN
   ANCHORED NEARLY DIRECTLY S OF PNS...BUT WEAKENED SUBSTANTIALLY AS IT
   ACCELERATED NWD TOWARDS THE COAST. ALTHOUGH AIR MASS N OF THE WARM
   FRONT IS CHARACTERIZED BY UPPER 60S TO LOWER 70S SURFACE DEW
   POINTS...RR SOUNDINGS SUGGEST INSTABILITY IS QUITE LIMITED WITH POOR
   LAPSE RATES AMIDST A SATURATED THERMODYNAMIC PROFILE.
   NEVERTHELESS...WITH 15-20 KT 0-1 KM SHEAR NOTED IN MOB/EVX VWP
   DATA...A WATERSPOUT MOVING ASHORE AS A BRIEF TORNADO CANNOT BE RULED
   OUT.

   ..GRAMS/GOSS.. 08/18/2013


   ATTN...WFO...TAE...MOB...

   LAT...LON   30358827 30668829 30928793 30918669 30878626 30768582
               30538558 30348550 30108562 30138588 30148716 30138829
               30358827