000 AGXX40 KNHC 231849 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 300 PM EDT THU SEP 23 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... SHIPS AND BUOYS THIS AFTERNOON ARE GENERALLY RUNNING AROUND 15-20 KT OVER MUCH OF THE EASTERN AND CENTRAL GULF THIS AFTERNOON. THESE WINDS ARE DRIVEN BY THE GRADIENT BETWEEN RIDGING JUST N OF THE GULF COAST STATES AND TROUGHING OVER THE FAR SW GULF AND NEWLY FORMED TROPICAL DEPRESSION FIFTEEN IN THE CENTRAL CARIBBEAN. THE AREA OF 20 KT WINDS IS EXPECTED TO CONTINUE TO SHIFT E FRI AS THE RIDGING DRIFTS E AND LOWER PRES BUILDS FURTHER WITH THE INTENSIFYING TROPICAL CYCLONE IN THE CARIBBEAN. DIURNALLY DRIVEN N-NE 15-20 KT WINDS WILL OCCUR TONIGHT. BY THE WEEKEND...THE FORECAST IS MORE DEPENDENT ON THE STRENGTH AND LOCATION OF TROPICAL DEPRESSION FIFTEEN IN THE CARIBBEAN. THE OFFICIAL FORECAST THINKING KEEPS THE SYSTEM SOUTH OF THE GULF OF MEXICO...REACHING AS FAR N AS 20N ALONG THE YUCATAN COAST BY TUE BUT INTENSIFYING IT TO A HURRICANE SUN THROUGH TUE. LOOK FOR WINDS AND SEAS TO INCREASE IN THE S CENTRAL GULF OVER THAT TIME FRAME AS A RESULT. A COLD FRONT IS FORECAST TO DROP INTO THE N GULF WATERS OFF THE TEXAS COAST SUN THEN WILL EXTEND FROM NEAR APALACHEE BAY TO THE CENTRAL SW GULF BY TUE. CONFIDENCE IS VERY LOW IN THE FORECAST FOR THIS FRONT AS THE MODELS VARY GREATLY WITH THE STRENGTH AND POSITION OF A CUT OFF LOW OVER THE MISSISSIPPI VALLEY EARLY NEXT WEEK. CARIBBEAN SEA... NEWLY DEVELOPED TROPICAL DEPRESSION FIFTEEN IS NEAR 13.9N76.2W AT 1800 UTC. THE OFFICIAL FORECAST THINKING MOVES TROPICAL DEPRESSION FIFTEEN TO THE FAR E COAST OF HONDURAS AS A TROPICAL STORM LATE FRI AND ALLOWS IT TO SKIRT THE NORTH COAST OF HONDURAS THROUGH SAT BEFORE CURVING THE SYSTEM N ALONG THE YUCATAN COAST SUN THROUGH TUE AS A HURRICANE. OTHERWISE A TIGHT PRES GRADIENT BETWEEN THE TROPICAL CYCLONE AND ATLC RIDGING TO THE N-NE OF THE AREA WILL CONTINUE TO RESULT IN 20-25 KT WINDS TRAILING BEHIND THE SYSTEM. SOME OF THE MODELS SHOW THE DEVELOPMENT OF A TROUGH NEAR 75W BY SUN THAT THEY FORECAST TO CARRY NW TOWARD THE TROPICAL CYCLONE THROUGH TUE. CONFIDENCE IS LOW IN THIS SCENARIO AT THE MOMENT...BUT THERE IS INCREASING MODEL SUPPORT FOR SOME SORT OF TROUGH HERE EARLY NEXT WEEK. SW N ATLC AND TROPICAL N ATLC... RIDGING EXISTS JUST N OF THE AREA EXTENDING FROM 1027 MB HIGH PRES CENTERED NEAR 36N57W TO COASTAL SOUTH CAROLINA AND ALL THE WAY WESTWARD THROUGH CENTRAL TEXAS. MODERATE TO FRESH TRADES HAVE BECOME ESTABLISHED ACROSS THE REGION WITH REDUCED PERIOD SEAS FINALLY SUBSIDING TO 6-8 FT OUTSIDE OF THE BAHAMAS. THE HIGHEST WINDS AND SEAS ARE OVER THE SOUTHERN PORTION ALONG THE COASTS OF HISPANIOLA AND CUBA NEAR THE MOUTH OF THE WINDWARD PASSAGE. THESE TRADES WILL GRADUALLY DIMINISH AND SEAS WILL SUBSIDE AS HIGH PRES SHIFTS TO THE E WHILE THE AREA OF LOW PRES IN THE CARIBBEAN MOVES W-NW DECREASING THE PRES GRADIENT SAT THROUGH TUE. HOWEVER...CONFIDENCE DECREASES IN THE FORECAST MON AND TUE DUE TO UNCERTAINTY WITH THE CLOSED LOW EXPECTED TO DEVELOP OVER THE CENTRAL U.S. WARNINGS... SW N ATLC... .NONE. CARIBBEAN... .TROPICAL STORM WARNING S OF 17N BETWEEN 78W AND 84W...AMZ082. .TROPICAL STORM WARNING N OF 14N...AMZ084. TROPICAL N ATLC... .NONE. GULF OF MEXICO... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER