000 AGXX40 KNHC 181805 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 115 PM EST SUN NOV 18 2012 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... A RIDGE EXTENDS NE-SE FROM THE FL BIG BEND TO THE BAY OF CAMPECHE WITH A COASTAL TROUGH ANALYZED ALONG THE SW BAY OF CAMPECHE. NE LOW LEVEL WINDS AT 10-15 KT CONTINUE ACROSS THE GULF WITH SEAS 3-5 FT MOST AREAS...EXCEPT 15-20 KT E OF 92W WITH SEAS 5-6 FT OVER THE S-CENTRAL WATERS. THE RIDGE WILL SHIFT SLOWLY NW WITH THE GRADIENT RELAXING TONIGHT AND MON. GUIDANCE SUGGESTS HIGH PRESSURE WILL STRENGTHEN AGAIN WED AFTERNOON INTO EARLY THU INCREASING THE NORTHERLY FLOW TO 15-20 KT ACROSS THE E-CENTRAL AND SE WATERS. LIGHT LOW LEVEL RETURN FLOW BEGINS TO SET UP OVER THE NW WATERS THU NIGHT. BLENDED LATEST ECMWF... UKMET AND GFS WITH PREVIOUS OFFICIAL GRIDS. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... THE GRADIENT BETWEEN HIGH PRES OVER THE E GULF OF MEXICO AND WEAK LOW PRES OVER THE SE CARIBBEAN CONTINUES TO MAINTAIN N WINDS OF 20-25 KT ACROSS THE W-CENTRAL WATERS FROM 11-16N W OF 81W...WITH SEAS 6-7 FT. NLY 10-15 KT WINDS ARE OBSERVED ELSEWHERE W OF 79W...WHILE NE-E TRADES AT 10-15 KT AND SEAS 2-4 FT CONTINUE ACROSS THE CARIBBEAN E OF 79W...INCREASING TO 15-20 KT WITH SEAS 5-8 FT...ACROSS THE TROPICAL ATLC WATERS. THE GRADIENT WILL RELAX A LITTLE THROUGH MON...THEN TIGHTEN AGAIN MON NIGHT INCREASING THE N-NE FLOW TO 15-20 KT ACROSS THE AREA W OF 78W. AN ENE-WSW RIDGE WILL SHIFT S OVER THE NORTHERN PORTION OF THE TROPICAL ATLC ON TUE. THE 15-20 KT TRADES CURRENTLY OVER THE NORTHERN PART OF THE TROPICAL N ATLC ARE EXPECTED TO DIMINISH TO 10-15 KT TONIGHT...AND GRADUALLY BECOME SE-S ACROSS THE WATERS N OF 19N MON NIGHT...THEN DIMINISH TO 5-10 KT AROUND THE RIDGE EVERYWHERE N OF 15N TUE-FRI. THE GRADIENT OVER THE SOUTHERN TROPICAL WATERS WILL RELAX AS WELL SUPPORTING NE-E 10-15 KT MON-FRI. A WEAKENING COLD FRONT WILL MOVE INTO THE ATLC WATERS N OF THE VIRGIN ISLANDS LATE THU NIGHT INTO EARLY FRI. SW N ATLC W OF 55W... A N-S ORIENTATED STATIONARY FRONT EXTENDS ALONG 78W N OF THE BAHAMAS WITH N-NE FLOW AT 20-25 KT...SEAS 8-13 FT...OBSERVED W OF THE FRONT. A BROAD TROUGH EXTENDS FROM 31N66W TO 22N70W WITH SCT RW/ISOL TS OBSERVED E OF THE TROUGH TO 55W. THE LOW LEVEL FLOW IS NE AT 10-15 KT BETWEEN THE TROUGH AND THE FRONT...AND SE 15 KT E OF THE TROUGH. GUIDANCE GENERALLY SUGGESTS WEAK SURFACE LOWS WILL DEVELOP ALONG BOTH THE STATIONARY FRONT AND THE LOW LEVEL TROUGH. THE WESTERN LOW WILL MOVE NE DRAGGING THE FRONTAL REMNANTS E WHILE THE EASTERN LOW TRACKS ROUGHLY NNW. LOOKS LIKE A COMPLEX LOW PATTERN LATE MON ALONG 30-32N W OF BERMUDA WITH THE TROUGHS MERGING OVER THE ATLC WATERS BETWEEN 65-72W. THE LOWS WILL MERGE JUST N OF THE AREA BY EARLY TUE...THEN PASS E OVER...OR JUST TO THE N OF...BERMUDA ON WED DRAGGING A COLD FRONT INTO THE NW WATERS AROUND SUNSET MON WITH THE FRONT REACHING FROM BERMUDA ACROSS THE CENTRAL BAHAMAS TO CENTRAL CUBA WED...AND PASSING THROUGH THE SE WATERS THU NIGHT. THE GFS IS HINTING AT A MINIMAL GALE W OF THE FRONT ROUGHLY N OF 30N BETWEEN 70-75W ON THU...BUT OTHER GUIDANCE IS CURRENTLY NOT AS STRONG. USED A BLEND OF GFS...UKMET AND ECMWF WITH PREVIOUS OFFICIAL GRIDS FOR PACKAGE. NOTE...GRIDDED MARINE FORECAST IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE GULF OF MEXICO... .NONE. CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. SW N ATLANTIC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER NELSON