ZCZC SPCSWOMCD ALL
ACUS11 KWNS 070030 
SPC MCD 070030 
FLZ000-070300-

MESOSCALE DISCUSSION 1772
NWS STORM PREDICTION CENTER NORMAN OK
0730 PM CDT THU OCT 06 2016

AREAS AFFECTED...PORTIONS E-CENTRAL/NERN FL IMMEDIATE COASTAL AREA.

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 070030Z - 070300Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...THIN SLIVER OF E-CENTRAL/NERN FL COASTAL AREA GENERALLY
BETWEEN VRB-JAX WILL HAVE MRGL TORNADO RISK THROUGH REMAINDER OF
EVENING INTO OVERNIGHT HOURS.  POTENTIAL WILL SHIFT GRADUALLY NWD
WITH TIME AND IN STEP WITH TRANSLATION OF TC.  RISK IS TOO LOW AND
CONDITIONAL TO WARRANT WW ATTM...BUT A BRIEF/WEAK TORNADO CANNOT BE
ENTIRELY RULED OUT.

DISCUSSION...BASED ON LATEST NHC FCST TRACK AND WIND FIELDS -- WHICH
SERVE FOR THIS PURPOSE AS PROXY FOR STORM SIZE -- MOST FAVORABLE
SECTOR OF HURRICANE MATTHEW FOR SUPERCELLS AND TORNADOES WILL REMAIN
OFFSHORE WELL INTO TONIGHT.  HOWEVER...WATERSPOUT MOVING ONSHORE OR
SMALL/BRIEF SUPERCELL TORNADO MAY OCCUR WITH CELLS GENERALLY
WEAKENING IN ORGANIZATION AS THEY MOVE ASHORE.  VWP AND AVBL RAOBS
SUGGEST ADEQUATE LOW-LEVEL SRH FOR ESPECIALLY WWD/RIGHT-MOVING CELLS
TO ROTATE...HOWEVER MAIN LIMITING FACTOR WILL BE LACK OF MORE ROBUST
BUOYANCY.  MLCAPE DECREASES RAPIDLY WITH INLAND EXTENT FROM
IMMEDIATE COAST...FROM OVER 1000 J/KG OFFSHORE TO AROUND 500 J/KG OR
LESS INLAND.  DIABATIC SFC COOLING WILL BE VERY SLOW/GRADUAL IN
PRESENCE OF THETAE ADVECTION ONSHORE FROM ATLC...BUT WILL ACT TO
DIMINISH INLAND CAPE EVEN FURTHER WITH TIME THROUGH TONIGHT. 
SECONDARY BUT STILL IMPORTANT FACTOR WILL BE CONVECTIVE MODE -- I.E.
WHETHER ANY RELATIVELY DISCRETE/SUSTAINED SUPERCELLS OFFSHORE CAN
SURVIVE VERY FAR MOVING RAPIDLY WWD/WSWWD INTO NWRN QUADRANT AIR
MASS CHARACTERIZED BY BOTH MUCH LOWER CAPE AND MESSIER PRECIP
STRUCTURES COMPARED TO OFFSHORE.  GIVEN THESE CONDITIONALITIES...
RISK IS NON-ZERO BUT TOO SMALL TO JUSTIFY WW ATTM.

REF NHC ADVISORIES FOR LATEST FORECAST TRACK...INTENSITY...SURGE...
TROPICAL WATCH...AND WARNING INFORMATION REGARDING MATTHEW.

..EDWARDS.. 10/07/2016

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...MLB...JAX...

LAT...LON   28058056 28338078 28908108 29478137 30018144 30238134
            29708121 29188096 28808072 28438049 28428055 28228058
            28058056 

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