000 AGXX40 KNHC 081959 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 255 PM EST FRI MAR 08 2013 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 SURFACE ANALYSIS SHOWS HAS HIGH PRES COVERING THE AREA AS A RIDGE EXTENDS FROM A STRONG 1034 MB HIGH LOCATED OVER THE UPPER GREAT LAKES S TO 25N90W AND TO THE YUCATAN PENINSULA. THE LATEST BUOY/PLATFORM AND SURFACE OBSERVATIONS INDICATE LIGHT SE FLOW W OF 89W...AND LIGHT NE-E WIND FLOW E OF 89W. THE OBSERVATIONS SHOW SEAS IN THE RANGE OF 3 TO 5 FT IN THE WESTERN PORTION OF THE GULF...AND 1 TO 3 FT OVER THE REMAINDER OF THE GULF. AS FOR THE FORECAST...MODELS IN GOOD AGREEMENT THAT THE HIGH PRES OVER THE AREA WILL WILL SLIDE EASTWARD TO THE WESTERN ATLC BY MON. THIS WILL ALLOW FOR SE RETURN FLOW OVER THE WESTERN PORTION TO EXPAND EASTWARD IN ADVANCE OF A COLD FRONT EXPECTED TO ENTER THE NW GULF WATERS SUN NIGHT. THE COLD FRONT WILL REACH FROM CENTRAL LOUISIANA TO THE BAY OF CAMPECHE MON MORNING...FROM THE FLORIDA BIG BEND REGION TO THE NE YUCATAN PENINSULA EARLY TUE...AND FROM THE FLORIDA KEYS TO NW CUBA AND JUST E OF THE NE YUCATAN PENINSULA TUE EVENING BEFORE PUSHING FURTHER E OF THE AREA TUE NIGHT. THE PRE GRADIENT BEHIND THE FRONT WILL BE TIGHTEN ENOUGH TO ALLOW FOR STRONG NORTHERLY WINDS BEHIND IT. THESE WINDS ARE EXPECTED TO INCREASE TO GALE FORCE OVER PORTIONS OF THE WESTERN GULF S OF 26N MON...HOWEVER THEY SHOULD BE SHORT-LIVED AS THEY WILL DIMINISH TO LESS THAN GALE FORCE BY MON NIGHT AS HIGH PRES SETTLES IN ACROSS THE AREA THROUGH WED WITH THE PARENT HIGH OVER THE FAR NW GULF. SW N ATLC S OF 31N W OF 65W... A WEAKENING COLD FRONT IS ANALYZED ACROSS THE SE WATERS...AND HAS USHERED IN A SET OF LARGE NW SWELLS. GALE FORCE WINDS THAT EARLIER OCCURRED IN THE NE PORTION OF THE FORECAST WATERS HAVE SINCE DIMINISHED. HIGH PRES IS BUILDING E FROM THE GULF OF MEXICO ACROSS THE WESTERN PORTION. THE FORECAST IS VERY SIMILAR TO THE PREVIOUS WITH RESPECT TO WINDS AND SEAS OVER MUCH OF THESE ZONES. THE COLD FRONT WILL DISSIPATE TONIGHT AS IT MOVES JUST E OF THE AREA. THE LARGE AND STRONG LOW PRES N OF THE AREA RESPONSIBLE FOR THE GALE FORCE IN THE NE PORTION...WILL BEGIN TO DROP S AFTER THIS EVENING...AND INTERACT WITH THE HIGH PRES BUILDING E ACROSS THE AREA TO ONCE AGAIN TIGHTEN THE PRES GRADIENT ACROSS MOST OF THE NORTHERN WATERS WITH ANOTHER ROUND OF GALE FORCE WINDS EXPECTED TO BEGIN N OF 29N E OF 72W EARLY TONIGHT BEFORE DIMINISHING TO JUST BELOW 35 KT LATER TONIGHT. THE LOW PRES IS THEN FORECAST TO SHIFT EAST AND SOUTHEAST FURTHER FROM THE REGION THROUGH SUN. ALTHOUGH WINDS WILL SLIGHTLY DIMINISH TO LESS THAN 30 KT SAT AND SUN OVER THE NORTHERN WATERS AND MOST OF THE CENTRAL WATERS...LARGE NW SWELLS WILL CONTINUE TO PLAGUE THE AREA MAINLY E OF THE BAHAMAS... WITH SEAS OF 15-21 FT E OF 77W ...AND 8-12 FT IN N SWELLS W OF 77W. BY TUE SEAS WILL BE IN THE 8-12 FT RANGE MOST ZONES E OF THE BAHAMAS WITH LINGERING 10-15FT SEAS IN NW SWELLS OVER THE FAR NE AND EASTERN PORTIONS. SOUTHERLY WINDS WILL INCREASE LATE MON/EARLY TUE OVER THE NW PART OF THE FORECAST AREA AHEAD OF THE NEXT COLD FRONT EXPECTED TO MOVE INTO THE FAR NW PART OF THE FORECAST AREA TUE AFTERNOON. THERE ARE SOME MODEL DIFFERENCES WITH RESPECT TO THE FORECAST POSITIONS OF THE FRONT ONCE IT MOVES OFF THE U.S. SE COAST. THE 12 UTC GFS SOLUTION IS FASTER THAN 12 UTC ECMWF SOLUTION WITH THE FRONT ACROSS THE NORTHERN WATERS. 12 UTC UKMET AND NOGAPS A TID FASTER THAN THE GFS WITH THE FRONT. FOR NOW SINCE THESE SOLUTIONS ARE FOR DAYS 4 AND 5 WILL GO WITH THE MORE CONSERVATIVE WITH THE FORECAST POSITIONS OF THIS FRONT...AND WAIT FOR UPDATED MODEL GUIDANCE TO SEE IT THEY COME INTO MORE OF CONSENSUS WITH THE TIMING. WILL FORECAST THE FRONT TO REACH A POSITION FROM NEAR 31N78W TO ACROSS CENTRAL FLORIDA NEAR DAYTONA BEACH BY LATE TUE NIGHT...AND FROM NEAR 31N73W TO CENTRAL BAHAMAS AND TO NW CUBA BY LATE WED. NWP MODELS IN REASONABLE AGREEMENT THAT NORTHERLY WINDS BEHIND THE FRONT WILL BE MOSTLY AT 20 KT WITH SOME 25 KT WINDS VERY POSSIBLY ALONG AND N OF 30N. THE NEW NOGAPS CAGIP GUIDANCE EVEN HINTS AT MOSTLY NW-N WINDS OF 20 KT BEHIND THE FRONT LATE TUE AND WED WITH 25 KT WINDS ALONG AND N OF 30N. THIS FRONT WILL USHER IN YET ANOTHER LARGE BATCH OF N SWELLS WITH SEAS MAXING OUT UP TO 10 FT BEHIND THE FRONT N OF THE BAHAMAS LATE TUE AND WED. CARIBBEAN SEA AND TROPICAL N ATLC S OF 22N W OF 55W... ASCAT/WSAT DATA FROM THIS MORNING SHOWED PREDOMINATELY NE FLOW OF 15-20 KT ACROSS THE WESTERN AND CENTRAL CARIBBEAN WITH SOME INDICATION OF HIGHER WINDS...IN THE 20-25 KT RANGE ...OVER THE FAR SRN WATERS OF THE CENTRAL CARIBBEAN NEAR THE COAST COLOMBIA AND NW VENEZUELA. A SWATH OF NE 20 KT WINDS WAS CAPTURED TO THE SW OF THE EASTERN PART OF CUBA. THE 1254 UTC ASCAT PASS INDICATED LIGHT NE-E WINDS OVER THE CENTRAL AND SOUTHERN PORTIONS OF THE TROPICAL N ATLC...AND SE-SE LIGHT OVER THE REMAINDER OF THOSE WATERS. OBSERVED SEA STATE REVEALS SEAS OF 4-6 FT OVER THE CENTRAL PORTION...AND 2-4 FT ELSEWHERE. HIGHER SEAS OF 6-8 FT ARE IN THE FAR SW PORTION NEAR THE COAST OF COLOMBIA. HIGH PRES OVER THE FAR NW CARIBBEAN SEA WILL SHIFT ENE THROUGH SUN. NORTHERLY SWELLS WILL PRODUCE LARGE SEAS THROUGH ALL NE CARIBBEAN EXPOSED PASSAGES...THE NE CARIBBEAN OFFSHORE WATERS AND ACROSS MOST OF THE TROPICAL N ATLC WATERS THROUGH WED. SEAS HEIGHTS WITH THESE SWELLS ARE EXPECTED TO REACH 10 OR 11 FT CREATING RATHER HAZARDOUS MARINE CONDITIONS OVER THESE WATERS. NOTE...GRIDDED MARINE FORECAST IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE WARNINGS... GULF OF MEXICO... .GALE CONDITIONS EXPECTED MON S OF 26N W OF 94W...GMZ17 AND GMZ023. CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. SW N ATLC... .GALE WARNING N OF 29N E OF 72W THROUGH SAT...AMZ113 AND AMZ115. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER AGUIRRE