000 AGXX40 KNHC 281948 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 145 PM EST FRI NOV 28 2008 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO... CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. RADIOFAX SCHEDULE FOR GRAPHICAL WIND WAVE...SURFACE FORECAST AND PEAK WAVE PERIOD CHARTS HAS CHANGED. FOR THE ATLANTIC BASIN THIS INCLUDES 24...36...48 AND 72 HOUR WIND WAVE..24...48..72 HOUR SURFACE FORECAST AND 48 AND 72 HOUR PEAK WAVE PERIOD CHARTS. FOR ADDITIONAL INFORMATION PLEASE REFER TO THE FAX SCHEDULE ON THE NHC WEB SITE AT HTTP://WWW.NHC.NOAA.GOV/RADIOFAX.SHTML GULF OF MEXICO... RIDGE AXIS EXTENDS ALONG 25N E OF 90W EARLY THIS AFTERNOON MAINTAINING LITTLE CHANGE TO PRESENT WIND AND SEA SATE CONDITIONS CURRENTLY BEING OBSERVED...WITH THE EXCEPTION OF THE WESTERN GULF WHERE SLY RETURN FLOW IS INCREASING. THIS WILL CONTINUE TO BE THE CASE AS THE RIDGE CONTINUES TO SLIDE EASTWARD...TO E OF THE AREA ON SAT. AS THIS HAPPENS...A STRONG COLD FRONT IS EXPECTED TO MOVE INTO THE TEXAS COAST EARLY ON SAT MORNING AND REACH FROM 30N89W TO NE MEXICO EARLY SAT EVENING...FROM THE FLORIDA BIG BEND TO WESTERN BAY OF CAMPECHE SUN AFTERNOON...THEN MOVE E OF GULF MON MORNING. ONCE THE FRONT REACHES THE FAR WESTERN GULF ON SAT...IT MAY AT FIRST LAG IN MOTION BUT THEN BECOME ENERGIZED WITH RESPECT TO ITS ASSOCIATED WIND FIELD LATER ON SAT AS A RATHER POTENT UPPER LEVEL TROUGH STARTS TO DIG SWD INTO THE NW GULF. THE TROUGH WILL BECOME ESTABLISHED AS A LONGWAVE TYPE WITH ITS AXIS SWINGING E ACROSS THE GULF THROUGH LATE ON TUE...WHILE THE SURFACE FRONT THEN QUICKLY MOVES THE GULF. HAVE DECIDED TO BACK OFF ON ISSUING GALE WARNINGS BASED ON LATEST SUITE OF NWP MODELS AND GFS MEAN ENSEMBLE GUIDANCE FROM 12 UTC THIS MORNING. WILL GO WITH NW-N WINDS OF 20-30 KT BEHIND THE FRONT SUN THROUGH MON WITH SW WINDS OF 20-25 KT SE OF THE GULF WITH MENTION OF GUSTS TO 30 KT SUN AND SUN NIGHT IN THE MIDDLE PORTION OF THE GULF. WILL FOLLOW WAVEWATCH GUIDANCE CLOSELY WITH SEAS OF 9-13 FT BUILDING BEHIND FRONT SUN THROUGH MON...ALTHOUGH WILL HAVE TO CONSIDER FUTURE UPDATES TO SEAS AS CONDITIONS AS CONDITIONS WARRANT. NWP MODELS ARE IN GOOD AGREEMENT THAT THE COLD FRONT EXITS THE GULF MON MORNING...FOLLOWED BY STRONG CONTINENTAL HIGH PRES THAT BUILDS THROUGHOUT THE AREA THROUGH MON. THE HIGH THEN WEAKENS TUE OVER THE NE GULF BEFORE SHIFTING TO THE SE UNITED STATES ON WED. MODELS ALSO AGREE THAT SLY RETURN FLOW INCREASES OVER THE WESTERN GULF TUE AND WED AS LOW PRES DEEPENS OVER THE SOUTHERN GREAT PLAINS. CARIBBEAN SEA AND TROPICAL NORTH ATLANTIC OCEAN... WINDS AND SEAS CONTINUE TO BE ON THE RATHER LOW SEAS OVER JUST ABOUT THE ENTIRE AREA...WITH THE EXCEPTION OF THE AREA E OF 75W INCLUDING THE WINDWARD PASSAGE WHERE TH PRES GRADIENT IS SLIGHTLY STRONGER ALLOWING FOR NE-E WINDS OF 15-20 KT. ALSO...THERE REMAINS THE ISSUE OF LONG PERIOD N-NE SWELLS OF 6-8 FT AFFECTING THE FAR E CARIBBEAN WATERS AND ATLC PASSAGES. THESE SWELLS ARE EXPECTED TO 6 FT BY SAT MORNING...BUT REMAIN AT 6-7 FT OVER THE NW PORTION OF THE TROPICAL N ATLC THROUGH SAT AFTERNOON ACCORDING MODEL WAVE GUIDANCE. THE GULF OF MEXICO COLD FRONT MENTIONED ABOVE IS FORECAST TO ENTER THE NW CARIBBEAN WATERS MON MORNING. UNTIL THEN...WINDS AND SEAS WILL BE RATHER LIGHT OVER JUST ABOUT ALL ZONES IN THE FORECAST AREA...EXCEPT PRESENTLY IN THE NW CARIBBEAN WINDS ARE NE 15-20 KT N OF 15N E OF 82W BUT WILL DIMINISH TO 10-15 KT TONIGHT. BEHIND THE FRONT WINDS WILL INCREASE TO NW-N 20-25 KT MON. THE FRONT WILL THEN REACH A PSN FROM E CUBA TO THE SW CARIBBEAN SEA LATE MON...AND FROM NEAR THE WINDWARD PASSAGE TO FAR SW CARIBBEAN SEA ON TUE AFTERNOON THEN SLOW DOWN...AND BE NEAR THE SAME LOCATION ON WED BUT AT A WEAKER STATE. WINDS WILL WEAKEN BEHIND THE FRONT OVER THE NW PORTION OF THE NW CARIBBEAN SEA TUE AND WED AS HIGH PRES SETTLES IN OVER THE E GULF OF MEXICO. WINDS SHOULD REMAIN N 20-25 KT WITH 25-30 KT WINDS NEAR THE COAST OF HONDURAS AND NORTHERN COSTA RICA ON TUE IN TIGHT GRADIENT SQUEEZE MUCH LIKE WHAT WAS OBSERVED DURING THE PAST FRONTAL EVENT THAT OCCURRED ABOUT 2 WEEKS WHERE 30 KT WINDS WERE NOTICED OVER PORTIONS OF THE NW AND SW CARIBBEAN SEA. CAN'T RULE OUT A BRIEF INSTANCE OF THESE WINDS REACHING MINIMAL GALE FORCE ON TUE ALONG THE COAST OF NICARAGUA. WILL MONITOR NEW MODEL GUIDANCE AS IT BECOMES AVAILABLE TO SEE IF TREND TOWARDS STRONG WINDS CONTINUES BEHIND THE FRONT NEAR THE COAST OF CENTRAL AMERICA EARLY NEXT WEEK. EXPECT SEAS TO BUILD UP TO POSSIBLY 11 FT BEHIND THE FRONT IN THE SW SECTION OF THE SEA TUE...AND TO 8 OR 9 FT IN THE NW SECTION. OF COURSE...SEAS WILL REACH HIGHER HEIGHTS ON TUE IF WINDS DUE EXCEED 30 KT. ELSEWHERE ACROSS THE CARIBBEAN SEA...TRADES WILL BE LIGHT THROUGH TUE (IN ABOUT THE 10-15 KT RANGE) WITH SEAS GENERALLY 3-5 FT...EXCEPT 5-6 FT IN THE EASTERN CARIBBEAN EXCEPT AS DESCRIBED IN FIRST PARAGRAPH...AND ACROSS MUCH OF THE W CARIBBEAN AS HIGH PRES N OF THE AREA RETREATS EASTWARD IN ADVANCE OF THE COLD FRONT PORTION THAT MOVES ACROSS THE WESTERN ATLC. SEAS BUILD IN THE E CARIBBEAN AGAIN TO 8 FT...AND TO 10 FT OVER THE TROPICAL N ATLC BEGINNING LATE MON THROUGH WED AS CENTRAL ATLC HIGH PRES STRENGTHENS ELY WINDS AND RESULTING SEAS THROUGHOUT THESE AREAS. SW N ATLC... A DISSIPATING COLD FRONT EXTENDS FROM 24N65W TO 23N69W EARLY THIS AFTERNOON WITH LIGHT N-NE WINDS OF 5-10 KT NEAR THE FRONT AND SEAS 4-6 FT IN N SWELL AS REPORTED BY BUOY DATA NOT TOO FAR AWAY FROM THE FRONT. LONG PERIOD N SWELLS OF 6-8 FT CONTINUE OVER THE AREA E OF 68W...AND WILL SLIGHTLY SUBSIDE THROUGH WED. WEAK HIGH PRES CENTERED OVER THE NW BAHAMAS WILL SHIFT E THROUGH SAT...AND TO E OF 65W ON SUN WITH A RIDGE SW THROUGH 27N65W TO SE BAHAMAS. THIS IN ADVANCE OF THE GULF OF MEXICO COLD FRONT DESCRIBED ABOVE MAKES EASTWARD PROGRESS THROUGH THE NW PORTION OF THESE WATERS LATE SUN. GALE FORCE WINDS ARE EXPECTED ON BOTH SIDES OF THE FRONT. WINDS BEHIND THE FRONT SHOULD DECREASE TO 20-30 KT ON MON MORNING WITH THE STRONGEST WINDS WITHIN 300 NM W OF THE FRONT AND N OF 30N. THE FRONT IS EXPECTED TO EXTEND FROM 31N74W TO CENTRAL CUBA BY MON EVENING...AND FROM 31N65W TO NEAR HAITI BY LATE ON TUE...AND WEAKENING FROM 27N65W TO NEAR HAITI BY WED MORNING. NW WINDS BEHIND DOWN TO MOSTLY NW 20 KT. SEAS WILL BE ON THE HIGH SIDE WITH MAXIMUM SEAS 10-16 FT W OF THE FRONT N AND NE OF THE BAHAMAS ON MON AND TUE. A SHORT PERIOD OF GALE FORCE WINDS OF 25-35 KT IS EXPECTED AHEAD OF THE FRONT LATE SUN INTO MON N OF 28N BETWEEN 72W-77W BEFORE DECREASING TO 20 KT LATE MON. THIS IS BASED ON MODEL PERSISTENCE AND ENSEMBLE PERCENTAGES OF GALE WINDS NOW TOUCHING 31N...AND TO JUST S OF 31N LATE SUN NIGHT INTO MON MORNING. BY WED WINDS WILL BE NE 20-25 KT ALONG AND JUST NW OF THE FRONT...AND NE 10-15 KT ELSEWHERE NW OF FRONT. SE OF FRONT...WINDS WILL GENERALLY BE E 10-15 KT...EXCEPT VARIABLE MOSTLY S-SW 5-10 KT N OF 26N. SEAS WILL RANGE 7-10 JUST NW OF THE FRONT...AND 4-7 FT ELSEWHERE WITH THE HIGHEST OVER THE SE PART IN INCREASING E SWELL. ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER AGUIRRE. TROPICAL PREDICTION CENTER.