000 AGXX40 KNHC 111901 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 300 PM EDT MON OCT 11 2010 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... 1018 MB HIGH PRES IS CENTERED OVER THE NE CENTRAL GULF OF MEXICO EXTENDING SW TO MEXICAN COAST...WITH MAINLY LIGHT WINDS FOUND ACROSS THE GULF....WITH 15 KT IN SLY FLOW FOUND ACROSS FAR W GULF COASTAL ZONES. THE PRES GRADIENT REMAINS RELATIVELY TIGHT OVER THE SE GULF BETWEEN THIS HIGH AND DEVELOPING LOW PRES TO THE S OVER THE WESTERN CARIBBEAN. NE WINDS 15 KT ARE FLOWING THROUGH THE STRAITS OF FLORIDA. THIS HIGH PRES WILL DRIFT W-SW DURING THE NEXT 2 DAYS AHEAD OF AN APPROACHING COLD FRONT WED. THE MODELS ARE GENERALLY IN GOOD AGREEMENT ON BRINGING THE COLD FRONT TO THE NW GULF COAST EARLY WED MORNING AND DISSIPATE IT AS IT SINKS S ACROSS THE CENTRAL GULF WED NIGHT AND THU. NLY WINDS BEHIND THE FRONT WILL REACHING 20 KT ACROSS THE WESTERN HALF OF GULF WED NIGHT INTO THU MORNING WHEN A SECONDARY SURGE OF COLD AIR MOVES IN BEHIND THIS FRONT WHICH WILL PASS THROUGH MUCH OF THE GULF BY FRI. SOME INCREASE IN WINDS ACROSS THE SRN HALF OF GULF IS POSSIBLE AS DEVELOPING LOW IN W CARIBBEAN LIFTS NW TO NEAR COZUMEL BY WED...THEN MAKES A VERY SLOW TURN NE THEN E THU AND FRI. INCREASED PRES GRADIENT BETWEEN THIS TROPICAL LOW AND HIGH PRES ACROSS THE CENTRAL PLAINS WILL LIKELY INDUCE STRONG NLY FLOW W OF 90W AND FRESH TO STRONG NE TO E WINDS THROUGH THE STRAITS AND ACROSS SE GULF. SW N ATLC AND TROPICAL N ATLC... HIGH PRES WILL BUILD ALONG 31N SUN THROUGH TUE WITH MOSTLY LIGHT WINDS IN THE SW N ATLC N OF 27N AND ELY WINDS IN THE 10 TO 15 KT RANGE IN MUCH OF THE AREA S OF 25N EXCEPT OVER THE SE PORTION OF THE SW N ATLC AND THE NORTHERN HALF OF THE TROPICAL N ATLC S OF A SURFACE TROUGH LEFT OVER THE REGION IN THE WAKE OF OTTO. RECENT MODEL RUNS HAVE DIFFERED ON SPECIFICS OF THE STRENGTH AND NUMBER OF SURFACE WAVES THAT DEVELOP ALONG THIS TROUGH...BUT OVERALL KEEP THE TROUGH MEANDERING IN THE SAME GENERAL AREA IN THE SE PORTION OF THE SW N ATLC ZONE UNTIL IT SHIFTS E LATE TUE. SINCE CONFIDENCE IS LOW IN THE MODEL HANDLING OF ANY OF THESE WAVES...A BLEND OF SOLUTIONS HAS BEEN USED WHICH KEEPS WINDS LESS THAN 20 KT N OF THE TROUGH. MORE UNCERTAINTY COMES INTO THE FORECAST BY LATE WED WHEN THE MODELS GENERALLY AGREE ON SHEDDING SOME SHORTWAVE ENERGY NORTHEASTWARD FROM THE NW CARIBBEAN THROUGH CUBA AND THE BAHAMAS ON ITS WAY TOWARD BERMUDA BY FRI. A SURFACE TROUGH IS EXPECTED TO DEVELOP IN ASSOCIATION WITH THIS ENERGY...WITH NE WINDS EXPECTED TO BUILD ON THE W SIDE OF THE TROUGH AS IT STRETCHES NORTHEAST. THE MODELS DIFFER ON THE STRENGTH OF THE TROUGH AND WINDS AROUND IT. THE GFS DEVELOPS A SPOT LOW ON THE TROUGH...BUT IT IS ON THE MORE VIGOROUS SIDE OF THE MODEL CONSENSUS ALONG WITH THE CMC WHILE THE UKMET AND ECMWF ARE WEAKER AND MORE EASTERLY. THE MODELS DO AGREE THAT THIS ENERGY WILL BE PICKED UP BY THE AMPLIFYING DEEP LAYER TROUGH EXPECTED TO MOVE OFF THE SE COAST THU AND FRI. THE GFS IS ALSO ON THE FASTER SIDE OF THE CONSENSUS WITH THE SURFACE COLD FRONT ASSOCIATED WITH THIS DEEP LAYER TROUGH. THEREFORE...ADJUSTED THE GFS TOWARD A SLOWER COLD FRONT MOVING OFF THE N FL COAST AND A WEAKER TROUGH STRETCHING INTO ITS LEADING EDGE AS IT MOVES THROUGH THE BAHAMAS THU/FRI. MEANWHILE...WINDS REMAIN UNDER 20 KT IN THE TROPICAL N ATLC THROUGH THE PERIOD. CARIBBEAN SEA... A BROAD AREA OF LOW PRESSURE LOCATED OVER THE SOUTHWESTERN CARIBBEAN HAS BECOME BETTER ORGANIZED TODAY WITH A SMALL TIGHT LOW ALONG IT ALONG THE NE COAST OF HONDURAS ATTM...WITH RECON REPORTING FLIGHT LEVEL WINDS OF TROPICAL STORM FORCE. THUS THIS SYSTEM IS LIKELY TO BE CLASSIFIED A TROPICAL CYCLONE AT 5 PM. THE LATEST NHC FORECAST MOVES THIS LOW NW NEXT 48 HOURS...REACHING NEAR COZUMEL...THEN HALTS IT IN RESPONSE TO SINKING FRONTAL SYSTEM AND ASSOCIATED HIGH PRES ACROSS THE GULF...AND TURNS IT VERY SLOWLY NE THEN E ALONG 20.5N-21N. THIS WILL GIVE THIS SYSTEM OPPORTUNITY TO INTENSIFY FURTHER AND INCREASE GRADIENT WINDS ACROSS THE BROADER REGION. WINDS AND SEAS WILL THUS BE ON THE INCREASE ACROSS THE NW CARIB NEXT 48 HOURS AND BEYOND...LIKELY REACHING TO NEAR 11 FT BY MORNING IN NE QUAD OF LOW. STRONGEST WINDS INITIALLY LIKELY TO REMAIN CLOSE...WITHIN 60-90 NM PER CURRENT STLT SUGGESTIONS. TROPICAL WAVE MOVING ACROSS CENTRAL CARIB TO E TIP OF HISPANIOLA ATTM HAS FRACTURED AND WILL MOVE W TO NEAR 77/78W BY 12Z TUE...AND THEN TO 81/82W BY WED MORNING...THEN BECOME ABSORBED IN CYCLONIC GYRE ACROSS CENTRAL AMERICA AND FAR TROPICAL EPAC. E TO SE WINDS 20 KT WILL BUILD ACROSS THE BASIN BEHIND THIS WAVE...AND 20-25 KT ACROSS THE SRN CARIB WHERE SEAS WILL BUILD TO 8 FT TONIGHT AND TO 9 FT TUE. W AND SW SWELL GENERATED FROM ANY TROPICAL CYCLONE WED AND BEYOND WILL AFFECT THE W AND SW COASTS OF THE GREATER ANTILLES...ESPECIALLY CUBA AND JAMAICA. WARNINGS... SW N ATLC... .NONE. CARIBBEAN... .NONE. TROPICAL N ATLC... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER STRIPLING