000
AGXX40 KNHC 231851
MIMATS

MARINE WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
250 PM EDT TUE OCT 23 2012

MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA 
AND TROPICAL N ATLC...AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W.

GULF OF MEXICO...
1023 MB HIGH CENTERED ALONG COAST OF CAROLINAS COMBINING WITH 
OLD FRONTAL ZONE/SHEARLINE STRETCHED ENE-WSW THROUGH CENTRAL 
BAHAMAS TO NW CUBA AND MAINTAINING FRESH ENE WINDS THROUGH 
STRAITS AND ACROSS EXTREME SE GULF. OTHERWISE...MODERATE E TO SE 
FLOW PREVAILS. BUOYS ACROSS SE QUARTER OF GULF SHOWED SEAS TO 8 
FT IN PREVAILING ENE FLOW OF PAST 24 HOUR. HIGH WILL SHIFT 
SLOWLY E NEXT 48 HOURS AS SANDY BEGINS TO SLOWLY LIFT OUT OF 
CARIB AND TIGHTEN GRADIENT EVEN FURTHER ACROSS SE AND E PORTIONS 
OF GULF...WHILE SLOWLY BACKING. GFS SEEMS TO BE MODEL OF CHOICE 
REGARDING SANDY AND THUS WW3 SHOULD YIELD GOOD RESULTS. SEAS TO 
BUILD TO 6-9 FT ACROSS SE GULF BY THU MORNING AND 9-12 FT 
THROUGH THE STRAITS...AND POSSIBLY 15-18 FT WITHIN THE FLORIDA 
CURRENT IN SWELL VS CURRENT SCENARIO. BROADENING OF WIND FIELD 
OF SANDY AS IT MOVES THROUGH BAHAMAS WILL EXPAND N TO NE WINDS 
20-25 KT ACROSS MUCH OF E HALF OF BASIN BY FRI. 

SW N ATLC S OF 31N W OF 65W...
SHEARLINE MENTIONED ABOVE COMBINING WITH HIGH PRES TO THE NNW TO 
PRODUCE A BROAD ZONE OF 20-25 KT WINDS AND SEAS TO 8 FT NE OF 
THE N HALF OF BAHAMAS AND THROUGH THE STRAITS OF FLORIDA...WHILE 
FRESHENING EASTERLIES TO THE S WILL CONTINUE TO INCREASE AS 
SANDY DEEPENS NEXT 24-36 HOURS. SANDY OF MAIN FOCUS OF FORECAST. 
HIGH PRES WILL REMAIN N AND NW OF SANDY AS IT EXITS CARIBBEAN 
NEXT 48 HOURS AND COMBINE WITH MONSOONAL ORIGINS TO PRODUCE VERY 
LARGE WIND FIELD SHIFTING NNE WITH SANDY. CURRENT NELY FETCH N 
OF SHEAR LINE ALREADY YIELDING 6-8 FT SEAS NE OF BAHAMAS AND 5-6 
FT ALONG THE FLORIDA COASTS. VERY DANGEROUS SCENARIO IS 
DEVELOPING WITH SANDY AS SUFFICIENTLY SLOW MOVEMENT...PRE 
EXISTING HIGH SEAS...VERY LARGE WIND FIELD...AND ONSHORE FLOW 
DURING HIGH LUNAR TIDES COULD SPELL EXTREME COASTAL FLOODING AND 
EROSION FOR FLORIDA AND CERTAINLY BAHAMAS WED NIGHT THROUGH SAT. 
WW3 FORECASTING 12 FT SEAS TO REACH CENTRAL FLORIDA COAST BY 18Z 
THU WITH SEAS BUILDING 20-35 FT WITHIN THE COASTAL WATERS BY 18Z 
FRI. THIS COULD EVOLVE INTO A HISTORICAL EVENT AND FO'S ARE 
ENCOURAGED TO ADVERTISE THIS EVENT VERY HARD. NELY SWELL WILL 
CONTINUE TO IMPACT FLORIDA AND SE COASTS THROUGH THE WEEKEND 
WITH LONGER PERIOD SWELL INDUCING SUSTAINED RUNUP.

CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W...
TROPICAL STORM SANDY CENTERED NEAR 13.8N 77.8W AT 1500 UTC AND 
CONTINUES TO SHOW IMPROVED STLT SIGNATURE PAST 12 HOURS...WITH 
DEEP CNVTN IMPROVING NEAR CORE. PRESENTLY...SSW TO S FLOW ON E 
SEMICIRCLE OF SANDY GENERATING LARGEST SEAS...WITH WAVE MODELS 
NOT HANDLING INITIAL STAGES OF STORM WELL YET. NAH VERSION OF 
WW3 LIKELY BEST AT INITIAL CONDITIONS...ALBEIT A BIT TO THE E OF 
PRESENT POSITION. LARGE WIND FIELD OF SANDY WILL PRODUCE BROAD 
CYCLONIC WIND FIELD AFFECTING THE ENTIRE BASIN W OF 63W BY 
THU...WITH SLY FLOW AND ASSOCIATED WIND SWELL LIFTING N WITH AND 
AFTER SANDY TO AFFECT CARIB COASTS OF HISPANIOLA STRONGLY. 
ACCELERATED SLY FLOW SHOULD BE EXPECTED THROUGH WINDWARD AND 
MONA PASSAGES THU NIGHT AND FRI. CONVERGENCE LINES OR A TAIL OF 
SANDY WILL LIFT N BEHIND SANDY'S EXIT THU THROUGH FRI...AND ADD 
TO TORRENTIAL RAINS EXPECTED ACROSS JAMAICA AND CUBA...AND 
AFFECT LAND AREAS BETWEEN 78W OVER CUBA AND HISPANIOLA... 
POSSIBLY TO INCLUDE JAMAICA. SANDY WILL LEAVE A VERY LARGE AND 
STRONG FOOT PRINT ACROSS THE REGION DURING THE NEXT SEVERAL 
DAYS! 

NOTE...GRIDDED MARINE FORECAST IS AVAILABLE AT 
WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE

GULF OF MEXICO...
.NONE.

CARIBBEAN SEA AND TROPICAL N ATLC...
.HURRICANE WARNING ZONE AMZ021.
.TROPICAL STORM WARNING ZONES AMZ021-031.

SW N ATLANTIC...
.NONE.
  
FOR ADDITIONAL INFORMATION PLEASE VISIT
WWW.HURRICANES.GOV/MARINE

$$
FORECASTER STRIPLING