MESOSCALE DISCUSSION 2263
   NWS STORM PREDICTION CENTER NORMAN OK
   0739 PM CDT TUE OCT 18 2011
   
   AREAS AFFECTED...SRN/CNTRL FL
   
   CONCERNING...TORNADO WATCH 867...
   
   VALID 190039Z - 190145Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 867 CONTINUES.
   
   WITH WW 867 SCHEDULED TO EXPIRE AT 02Z...A REPLACEMENT WW WILL BE
   COORDINATED AFTER 01Z.
   
   12Z WRF-NMM AND RECENT HRRR GUIDANCE ARE RATHER CONSISTENT THAT
   REGENERATING TSTM CLUSTERS WILL CONTINUE ACROSS SRN/CNTRL FL FOR THE
   NEXT SEVERAL HOURS. IMPRESSIVELY LARGE LOW-LEVEL HODOGRAPHS ACROSS
   CNTRL/SRN FL PER 00Z RAOBS AND VWP DATA WILL REMAIN QUITE FAVORABLE
   FOR POTENTIAL TORNADIC CIRCULATIONS THIS EVENING INTO THE OVERNIGHT
   WITH 0-1 KM SRH AOA 300 M2/S2.
   
   GREATEST NEAR-TERM TORNADO THREAT IS WITH A SUPERCELL IN WRN
   MIAMI-DADE COUNTY WITH FORECAST TRAJECTORY TOWARDS THE MIAMI METRO
   AREA. MODIFIED 00Z MIAMI RAOB SUGGESTS AIR MASS ACROSS SRN FL IS AT
   LEAST MODERATELY UNSTABLE WITH PW VALUES AROUND 2.50 IN.
   PROGRESSIVELY LESSER BUOYANCY WITH NRN EXTENT SHOULD LIMIT A MORE
   ROBUST TORNADO THREAT ROUGHLY NORTH OF A TAMPA BAY TO MELBOURNE
   LATITUDE.
   
   ..GRAMS.. 10/19/2011
   
   
   ATTN...WFO...MFL...MLB...KEY...TBW...
   
   LAT...LON   26507985 24978027 24538111 24348159 24718173 25748165
               26248188 27088235 27398227 27538203 27628143 27658072
               27698038 26507985