000 AGXX40 KNHC 041857 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 255 PM EDT FRI NOV 04 2011 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... LATEST SATELLITE IMAGERY SHOWS A NARROW LINE OF BROKEN TO OVERCAST LOW CLOUDS MARKING THE LEADING EDGE OF THE COLD FRONT THAT PUSHED INTO THE NW GULF THIS YESTERDAY NOW EXTENDING FROM NEAR NAPLES FLORIDA SW TO 23N87W...TO CENTRAL BAY OF CAMPECHE AND S TO TAMPICO MEXICO. LATEST AND RECENT BUOY OBSERVATIONS CLEARLY REVEAL THE VERY SHARP WIND SHIFT MARKING THE PASSAGE OF THE COLD FRONT. THE OBSERVATIONS SHOW WINDS BEHIND THE FRONT HAVE DIMINISHED TO N-NE 15-20 KT E OF 90W...AND 10-15 W OF 90W EXCEPT S OF 23N W OF FRONT WHERE WINDS ARE NW-N 20-30 KT BETWEEN FRONT AND THE MEXICAN COAST. BUOYS INDICATE THAT SEAS HAVE SUBSIDED TO 5-8 FT E OF 90W...AND 3-5 FT W OF 90W EXCEPT S OF 23N W OF FRONT WHERE SEAS ARE UP TO 10 FT IN LINGERING N TO NE SWELL. THE LATEST MODEL RUNS ARE IN PRETTY GOOD AGREEMENT THAT THE FRONT WILL QUICKLY REACH TO A PSN FROM THE FLORIDA KEYS SW TO THE EASTERN BAY OF CAMPECHE EARLY THIS EVENING...THEN EXIT THE GULF LATER TONIGHT AS STRONG HIGH PRES CONTINUES TO BUILD SE ACROSS THE GULF.THE HIGH WILL SHIFT SOME EASTWARD SUN AND MON AND WEAKEN ALLOWING FOR WINDS TO BECOME E TO SE ACROSS MUCH OF THE AREA. THE NEXT COLD FRONT IS FORECAST TO MOVE OFF THE TEXAS COAST EARLY TUE EVENING...REACH FROM NEAR SW LOUISIANA TO NE MEXICO BY LATE TUE NIGHT...AND FROM NEAR THE MOUTH OF THE MISSISSIPPI RIVER TO FAR WESTERN BAY OF CAMPECHE BY LATE WED FOLLOWED BY NW-N WINDS OF 20-25 KT AND SEAS BUILDING TO 8 FT. SW N ATLC S OF 31N W OF 55W... SATELLITE IMAGERY ALONG WITH BUOY OBSERVATIONS FROM LATE THIS MORNING AND EARLY THIS AFTERNOON REVEAL THAT THE COLD FRONT HAS MOVED OFF THE SE U.S. AND NE FLORIDA COASTS. IT EXTENDS FROM NEAR 31N78W SW TO MELBOURNE FLORIDA. THE BUOYS SHOW SW WINDS AHEAD OF THE FRONT INCREASING TO 20-25 KT WITH SEAS BUILDING TO 8-10 FT. WINDS BEHIND THE FRONT ARE NW 15-20 KT WITH SEAS OF 5-7 FT. SATELLITE IMAGERY ALSO SHOWS THE REMNANT CLOUD BOUNDARY OF A PREVIOUS COLD FRONT EXTENDING FROM NEAR 25N65W SW TO EASTERN HISPANIOLA. BUOYS AND SHIP OBSERVATIONS NEAR THE BOUNDARY SHOW NE WINDS OF 10-15 KT TO ITS NW...AND SE-S WINDS OF 10 KT TO ITS SE. OBSERVED SEA STATE SHOWS SEAS OF 5-7 FT IN A N SWELL SE OF THE BOUNDARY...AND HIGHER SEAS OF 6-8 FT IN A N TO NE SWELL TO THE NE AND E OF BAHAMAS...AND 4-6 FT ELSEWHERE EXCEPT 2-4 FT SW OF THE BAHAMAS. UPCOMING CHANGES TO THE FORECAST FOR THE AREA BEGINNING ON FRI REVOLVE AROUND A SOUTHERN STREAM SYSTEM EXPECTED TO STREAM OFF THE SOUTHEASTERN U.S. COAST. MODEL GUIDANCE CONTINUES TO DIFFER TO SOME EXTENT WITH THIS SYSTEM MOVING ACROSS THE SE U.S. PRESENTLY...LOW PRES HAS FORMED OVER THE CAROLINAS AND IS DEEPENING. THIS LOW IS ATTACHED TO THE AFOREMENTIONED COLD FRONT. THE GFS BRINGS THE LOW SE INTO THE N WATERS DURING THE WEEKEND. THE 12 UTC NOGAPS IS NOW SIMILAR TO THE GFS WITH THIS SCENARIO...BUT IS MUCH FURTHER TO THE S. THE 120O UTC ECMWF SHOWS A SLIGHTER WEAKER LOW ALSO MOVING INTO THE NRN PORTION OF THE AREA DURING THE WEEKEND...BUT IS SLIGHTER TO THE S OF THE GFS AT 24 HRS AND SLIGHTER TO THE W NEAR 27N69W BY 48 HRS AS 1011 MB. THE GFS IS NEAR 31N70W AT 24 HRS...AND NEAR 28N67W AT 48 HRS. THE GFS AND ECMWF TEND TO TAKE THE LOW IN SLOW MOTION BACK TO THE WNW MON THROUGH WED. THE OTHER MODELS TEND TO SHOW MORE OF BROAD TROUGH. AS THE LOW MOVES SE INTO THE AREA THROUGH SUN...IT WILL INTENSIFY SLIGHTLY BEFORE REACHING 31N73W EARLY SAT AS 1003 MB. THE COLD FRONT WILL REACH FROM NEAR 31N75W TO THE STRAITS OF FLORIDA EARLY TONIGHT. THE LOW WILL THAN REACH TO NEAR 28N70W 1009 MB BY SUN MORNING WITH THE COLD FRONT WEAKENING SW TO THE NEAR WINDWARD PASSAGE. THE LOW WILL BECOME STATIONARY BY LATE SUN INTO MON THEN DRIFT W TUE AND WITH FRONTAL TROUGH TO HISPANIOLA. A STRONG PRES GRADIENT DEVELOPING N OF THE LOW AND FRONT WILL RESULT IN GALE CONDITIONS OVER MUCH OF THE NORTHERN WATERS SAT INTO EARLY TUE. THE LOW AND WEAKENING FRONT MAY VERY WELL BECOME A BROAD TROUGH TUE AND WED. THE MAIN ISSUE WITH THIS UPCOMING SCENARIO WILL BE THE SIGNIFICANCE OF THE PRES GRADIENT TO THE N OF THE LOW AND COLD FRONT OVER THE NEXT FEW DAYS. THE GRADIENT WILL BECOME STRONG WITH NE-E GALE WINDS OF 35-45 KT DEVELOPING N OF 28N BEHIND THE FRONT ON SAT...WITH POSSIBLE STORM CONDITIONS JUST N OF THE AREA. NE GALE WINDS OF 25-35 KT WILL REMAIN N OF THE FRONT INTO MON BEFORE DIMINISHING LATER ON MON AND TUE. VERY LARGE SEAS OF UP TO 21 FT IN A NW SWELL WILL SPREAD INTO THE AREA BEHIND THE FRONT AND LOW...DIMINISHING ONLY SOME LATE SUN THROUGH TUE. BY WED WINDS SHOULD BE RATHER LIGHT THROUGHOUT WITH LINGERING SWELLS ALLOWING FOR SEAS UP TO 8 FT MAINLY N OF 26N W OF 77W. CARIBBEAN SEA AND TROPICAL N ATLC... BROAD LOW PRES WILL PERSIST OVER THE S CENTRAL CARIBBEAN THROUGH SUN NIGHT MAINTAINING GENERALLY LIGHT TO MODERATE NE TO E WINDS. A TROPICAL WAVE APPROACHING THE FAR EASTERN CARIBBEAN SEA WILL ENTER THE FAR EASTERN CARIBBEAN SEA EARLY TONIGHT...THEN MOVE ACROSS REMAINDER OF THE EASTERN CARIBBEAN THROUGH EARLY SUN AS IT WEAKENS. A COLD FRONT OVER THE FAR SE GULF OF MEXICO WILL ENTER THE FAR NW CARIBBEAN EARLY TONIGHT...THEN WEAKEN OVER THE N CENTRAL CARIBBEAN SAT THROUGH MON. HIGH PRES FROM THE EASTERN U.S. WILL BUILD S ACROSS THE NW CARIBBEAN SAT THROUGH MON...THEN WEAKEN LATE MON THROUGH WED. WARNINGS... GULF OF MEXICO... .NONE. .CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. .SW N ATLC... .GALE WARNING N OF 28N E OF 78W...AMZ080. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER AGUIRRE