000 AGXX40 KNHC 271810 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 210 PM EDT TUE SEP 27 2016 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W...AND THE SW N ATLANTIC INCLUDING THE BAHAMAS. ...GULF OF MEXICO... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS WEIGHTED TOWARD GFS. HIGH CONFIDENCE. A TROUGH WITH ACTIVE CONVECTION S OF 27N IN THE WESTERN GULF WILL DRIFT WEST AND WEAKEN THROUGH WED NIGHT. GENTLE TO MODERATE WINDS WILL CONTINUE E OF THE TROUGH...WITH MODERATE TO FRESH NORTHERLY WINDS EXPECTED W OF THE TROUGH. A COLD FRONT PUSHING INTO THE NORTHERN GULF THU WILL BECOME STATIONARY FROM CENTRAL FLORIDA TO THE SW GULF FRI...THEN DISSIPATE THROUGH SAT. EXPECT MODERATE TO LOCALLY FRESH NORTH TO NORTHEAST WINDS N OF THE FRONT THU NIGHT AND FRI. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS WEIGHTED TOWARD GFS. HIGH CONFIDENCE THROUGH FRI...THEN LOW AFTERWARDS. A WEAK TROPICAL WAVE ALONG 72W WILL MOVE ACROSS THE W CARIBBEAN THROUGH FRI. MAIN FOCUS THE NEXT SEVERAL DAYS WILL BE A STRONG TROPICAL LOW CENTERED NEAR 12N53W WHICH IS EXPECTED TO BECOME A TROPICAL CYCLONE LATER TODAY EAST OF THE WINDWARD ISLANDS. GALE FORCE WINDS ARE EXPECTED NORTH OF THE LOW CENTER AS IT CROSSES THE LESSER ANTILLES. BUOY 41040 NEAR 14.5N 53.0W HAS BEEN REPORTING 30 KT WINDS TODAY...AND SEAS BUILDING TO 13 FT. THIS INDICATES VERY STRONG WINDS AND HIGH SEAS ARE PRESENT NORTH OF THE LOW CENTER. FURTHER INTENSIFICATION OF THE LOW IS EXPECTED IN THE EASTERN AND CENTRAL CARIBBEAN WED THROUGH SUN. GLOBAL MODEL GUIDANCE IN VERY GOOD AGREEMENT THROUGH FRI...BUT BEGIN TO DIVERGE SIGNIFICANTLY THIS WEEKEND...SO CONFIDENCE IN THE FORECAST IS LOW SAT AND SUN. HAVE USED GFS AND WW3 MODEL GUIDANCE AS PRIMARY BASIS FOR THE GRID FORECASTS...BUT USERS SHOULD EXCERCISE CAUTION IN EXTENDED PORTION BEYOND DAY 3 OR 4. GFS MOVES THE LOW SHARPLY NORTHWARD THROUGH THE WINDWARD PASSAGE BETWEEN HAITI AND CUBA...WHILE THE EUROPEAN MODEL TAKES A SLOWER APPROACH NORTHWARD TOWARD CENTRAL CUBA AFTER A JOG SOUTHWARD IN THE WEST-CENTRAL CARIBBEAN. THE PRIMARY STEERING FACTOR WILL BE THE STRENGTH OF THE A MID-LEVEL TROUGH OVER THE EASTERN U.S. IN ALL LIKELIHOOD THIS LOW WILL BE CONSIDERED A TROPICAL CYCLONE WITHIN THE NEXT 6-24 HOURS. EXPECT TRANSITION TO TROPICAL CYCLONE CONDITION WORDING WITHIN THE OFFSHORES AND OTHER FORECAST PRODUCTS ONCE ADVISORIES ARE INITIATED BY THE NHC. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS WEIGHTED TOWARD GFS. HIGH CONFIDENCE THROUGH SAT...THEN LOW AFTERWARDS. HIGH PRESSURE CENTERED NEAR 36N60W AND A WEAK LOW CENTERED NEAR SAVANNAH GEORGIA IS SUPPORTING MODERATE SE TO S WINDS EAST OF 75W AND GENTLE SOUTHWESTERLY WEST OF 75W NORTH OF THE BAHAMAS. THE LOW WILL MOVE NE TONIGHT WHILE THE HIGH SHIFTS EASTWARD...AND ALLOW S TO SW WINDS TO PREVAIL OVER MOST OF THE FORECAST AREA. WINDS AND SEAS WILL INCREASE OVER SE WATERS WED AND THU AS A STRONG TROPICAL LOW...POSSIBLE TROPICAL CYCLONE...PASSES SOUTH OF THE AREA. WINDS AND SEAS WILL THEN INCREASE NORTH OF HISPANIOLA AND PUERTO RICO FRI AND SAT AS THE LOW SHIFTS FURTHER WEST. MODEL GUIDANCE IS IN GOOD AGREEMENT THROUGH FRI...BUT DIVERGE AFTERWARDS. AS A RESULT THERE IS CONSIDERABLE UNCERTAINTY IN THE FORECAST OVER SOUTHERN WATERS IN THE VICINITY OF HISPANIOLA...CUBA AND WINDWARD PASSAGE THIS WEEKEND. .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS II COLLABORATION CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... .AMZ021...CARIBBEAN FROM 15N TO 18N BETWEEN 72W AND 80W... GALE CONDITIONS POSSIBLE FRI INTO SAT NIGHT. .AMZ023...CARIBBEAN N OF 15N BETWEEN 64W AND 72W... GALE WARNING WED NIGHT INTO THU. GALE CONDITIONS POSSIBLE THU INTO SAT NIGHT. .AMZ025...OFFSHORE WATERS LEEWARD ISLANDS... GALE WARNING WED INTO THU. .AMZ027...TROPICAL N ATLANTIC FROM 15N TO 19N BETWEEN 55W AND 60W... GALE WARNING WED. .AMZ031...CARIBBEAN FROM 11N TO 15N BETWEEN 72W AND 80W INCLUDING COLOMBIA BASIN... GALE CONDITIONS POSSIBLE FRI INTO SAT NIGHT. .AMZ033...CARIBBEAN S OF 15N BETWEEN 64W AND 72W INCLUDING VENEZUELA BASIN... GALE WARNING WED NIGHT INTO THU. GALE CONDITIONS POSSIBLE THU INTO SAT NIGHT. .AMZ035...OFFSHORE WATERS WINDWARD ISLANDS INCLUDING TRINIDAD AND TOBAGO... GALE WARNING WED INTO THU. .AMZ037...TROPICAL N ATLANTIC FROM 07N TO 15N BETWEEN 55W AND 65W... GALE WARNING TONIGHT INTO WED. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT: HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT: HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP FOR ADDITIONAL INFORMATION PLEASE VISIT: HTTP://WWW.HURRICANE WARNINGS.GOV/MARINE $$ .FORECASTER MUNDELL. NATIONAL HURRICANE CENTER.