000 AGXX40 KNHC 200633 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 233 AM EDT THU OCT 20 2016 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO, CARIBBEAN SEA, AND TROPICAL NORTH ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W, AND THE SOUTHWEST NORTH ATLANTIC INCLUDING THE BAHAMAS. ...GULF OF MEXICO... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS. HIGH CONFIDENCE. RIDGING EXTENDING FROM THE SOUTH CAROLINA LOW COUNTRY IS CONTINUING TO WEAKEN AND SHIFT EAST AHEAD OF A COLD FRONT WHICH IS MOVING ACROSS THE SOUTHERN PLAINS TOWARD THE LOWER MISSISSIPPI VALLEY. A COUPLE OF WEAK SURFACE TROUGHS ARE IN THE WESTERN GULF, AND WILL DISSIPATE THROUGH THE MORNING AS THEY DRIFT TO THE WEST. THE LATEST OBSERVATIONS INDICATE MAINLY MODERATE EAST TO SOUTHEAST FLOW ACROSS THE BASIN, ALONG WITH SEAS OF 2 TO 4 FEET. THE COLD FRONT IS FORECAST TO APPROACH THE TEXAS COAST THROUGH THE DAY, MOVING OFFSHORE INTO THE NORTHWEST GULF TONIGHT. THE FRONT WILL QUICKLY MOVE TO THE EAST ACROSS THE BASIN, EXTENDING FROM APALACHEE BAY FLORIDA TO NEAR TAMPICO, MEXICO BY EARLY FRIDAY, FROM NEAR TAMPA BAY, FLORIDA TO VERACRUZ, MEXICO FRIDAY NIGHT, PUSHING SOUTHEAST OF THE GULF WATERS SATURDAY NIGHT. MODEL GUIDANCE INCLUDING SREF 34-KT WIND PROBABILITIES, INDICATE THAT GALE FORCE WINDS ARE LIKELY BEHIND THE FRONT ALONG THE COAST OF TAMPICO, MEXICO STARTING FRIDAY AFTERNOON INTO THE EVENING, AND SPREADING SOUTHWARD ALONG VERACRUZ, MEXICO BY FRIDAY EVENING, THEN PERSISTING THROUGH THE DAY SATURDAY BEFORE DIMINISHING SATURDAY EVENING. HIGH PRESSURE WILL BUILD DOWN FROM THE NORTH IN THE WAKE OF THE FRONT, MOVING ACROSS CENTRAL GEORGIA BY SUNDAY MORNING, THEN WEAKENING ACROSS THE SOUTHEAST U.S. EARLY NEXT WEEK AS A NEW COLD FRONT DROPS IN FROM THE NORTH. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS. HIGH CONFIDENCE. A RELATIVELY WEAK PRESSURE PATTERN CONTINUES TO PREVAIL ACROSS THE BASIN. BROAD AND NEARLY STATIONARY SURFACE LOW PRESSURE TROUGHING CONTINUES TO PERSIST ACROSS THE CENTRAL CARIBBEAN, ROUGHLY ALONG 80W. THE LATEST OBSERVATIONS REPORT LIGHT AND VARIABLE WINDS ACROSS THE CENTRAL AND SOUTHWEST CARIBBEAN, WITH MODERATE NORTHEAST TO EAST FLOW IN THE NORTHWEST CARIBBEAN, AND MODERATE EAST TO SOUTHEAST FLOW IN THE EASTERN CARIBBEAN AND TROPICAL NORTH ATLANTIC, AROUND HIGH PRESSURE RIDGING WHICH EXTENDS FROM THE CENTRAL ATLANTIC TO JUST NORTH OF THE NORTHEAST CARIBBEAN ISLANDS. SEAS ARE 1 TO 3 FEET IN THE CENTRAL AND SOUTHWEST CARIBBEAN, 2 TO 4 FEET IN THE NORTHWEST CARIBBEAN, WITH 3 TO 5 FEET IN THE EASTERN CARIBBEAN, AND 5 TO 7 FEET IN THE TROPICAL NORTH ATLANTIC DUE TO DECAYING NORTHERLY SWELLS. LITTLE CHANGE IN THE WEATHER PATTERN AND MARINE CONDITIONS IS ANTICIPATED THROUGH EARLY SATURDAY. A COLD FRONT WILL APPROACH THE YUCATAN CHANNEL FROM THE GULF OF MEXICO DURING THE DAY SATURDAY, PUSHING INTO THE NORTHWEST CARIBBEAN SATURDAY EVENING, THEN STALLING FROM NEAR THE WINDWARD PASSAGE TO JUST NORTHWEST OF WESTERN JAMAICA, TO THE COAST OF EASTERN HONDURAS BY EARLY SUNDAY, WHERE IT WILL GRADUALLY WEAKEN AND BECOME DIFFUSE THROUGH EARLY NEXT WEEK. FRESH TO LOCALLY STRONG NORTH TO NORTHEAST FLOW WILL LIKELY FOLLOW THE FRONT ALONG WITH HAZARDOUS BOATING CONDITIONS NEAR AND THROUGH THE YUCATAN CHANNEL, ALONG WITH BUILDING SEAS. MODEL GUIDANCE VARIES LITTLE THROUGH THE FORECAST PERIOD. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS. HIGH CONFIDENCE. A SHARP INVERTED UPPER LEVEL TROUGH EXTENDS FROM WEST OF BERMUDA NEAR 32N70W, TO AN UPPER LEVEL CYCLONE LOCATED OVER THE WESTERN BAHAMAS. AN ELONGATED AREA OF SURFACE LOW PRESSURE IS LOCATED NEAR 26N70W, WITH SURFACE TROUGHING EXTENDING TO THE NORTHEAST TO NEAR 30N60W, AND TO THE SOUTHEAST TO NEAR THE WINDWARD PASSAGE. THE LATEST OBSERVATIONS INDICATE FRESH TO STRONG NORTHEAST TO EAST WINDS ON THE NORTHWEST SIDE OF THE SURFACE LOW AND TROUGHING OUT TO ABOUT 360 NM FROM THE LOW CENTER, WITH MODERATE TO FRESH NORTHEAST FLOW ELSEWHERE WEST OF THE SURFACE TROUGHING. MODERATE TO FRESH SOUTHEAST TO SOUTH FLOW IS OBSERVED ACROSS THE REMAINDER OF THE BASIN TO THE SOUTHEAST OF THE SURFACE TROUGHING. SEAS ARE 6 TO 9 FEET NORTHWEST OF THE TROUGHING, EXCEPT 7 TO 11 FEET ACROSS THE AREA OF THE STRONGEST WINDS, AND 6 TO 8 FEET ELSEWHERE, EXCEPT 1 TO 3 FT INSIDE OF THE BAHAMA BANKS. THE LOW IS FORECAST TO MOVE TO THE NORTHWEST THROUGH THIS EVENING, BEFORE TURNING TO THE NORTH LATE TONIGHT, AND EXITING OFF TO THE NORTHEAST THROUGH FRIDAY NIGHT AS A DEEP LAYERED UPPER TROUGH MOVES TOWARD THE U.S. EASTERN SEABOARD. THE LOW HAS A MEDIUM CHANCE FOR TROPICAL CYCLONE DEVELOPMENT DURING THE NEXT 48 HOURS. FRESH TO STRONG SOUTHERLY FLOW WILL PERSIST ACROSS THE NORTHEAST WATERS IN THE WAKE OF THE LOW FRIDAY NIGHT INTO EARLY SATURDAY AS THE LOW DRAGS THE TRAILING TROUGH ALONG WITH IT. A COLD FRONT WILL MOVE INTO THE NORTHWEST PORTION FRIDAY EVENING, REACHING FROM 31N72W TO THE FLORIDA KEYS EARLY SATURDAY, FROM BERMUDA TO THE SOUTHEAST BAHAMAS LATE SATURDAY NIGHT, THEN STALLING FROM NEAR 24N65W TO THE WINDWARD PASSAGE BY LATE SUNDAY NIGHT WHERE IT WILL GRADUALLY DECAY TO A REMNANT SHEAR LINE EARLY NEXT WEEK. EXPECT FRESH TO LOCALLY STRONG NORTH TO NORTHEAST FLOW BEHIND THE FRONT ALONG WITH BUILDING SEAS. .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS II COLLABORATION CHAT, OR BY TELEPHONE: .GULF OF MEXICO... .GMZ017...W CENTRAL GULF FROM 22N TO 26N W OF 94W... GALE WARNING FRI INTO FRI NIGHT. .GMZ023...SW GULF S OF 22N W OF 94W... GALE WARNING FRI NIGHT. GALE CONDITIONS POSSIBLE FRI NIGHT INTO SAT. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *FOR DETAILED ZONE DESCRIPTIONS, PLEASE VISIT: HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT: HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP FOR ADDITIONAL INFORMATION, PLEASE VISIT: HTTP://WWW.HURRICANES.GOV/MARINE. $$ .FORECASTER LEWITSKY. NATIONAL HURRICANE CENTER.