000 AGXX40 KNHC 241847 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 245 PM EDT SAT SEP 24 2011 UPDATED WARNINGS AND THE CARIBBEAN AND TROPICAL N ATLC W OF 55W SECTIONS FOR TROPICAL STORM OPHELIA. 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... THE 18 UTC PRELIMINARY SURFACE ANALYSIS SHOWS A WEAKENING STATIONARY FRONT EXTENDING FROM THE FLORIDA BIG BEND REGION SW TO 28N87W AND TO 28N91W. NE AND N CENTRAL GULF BUOYS SHOW N-NE WINDS OF 10 KT N OF THE FRONTAL BOUNDARY WITH SEAS OF 1 FT. A WEAK TROUGH EXTENDS FROM 27N85W TO 22N93W. A WEAK PRES PATTERN IS PRESENT ELSEWHERE ACROSS THE AREA WITH SEAS OF 1-2 FT. THE FRONTAL BOUNDARY IS FORECAST TO LIFT NWD WHILE DISSIPATING JUST INLAND THE COAST THROUGH MON. ATLC HIGH PRES WILL THEN BUILD WESTWARD ALONG 27N THROUGH TUE...AND SHIFT N TO ALONG 29N WED AND THU. ONSHORE FLOW WILL INCREASE OVER THE FAR WESTERN WATERS ON SUN AS LOW PRES DEVELOPING OVER THE SOUTHERN PLAINS INTERACTS WITH THE RIDGE TO INCREASE THE PRES GRADIENT THERE. THE ONSHORE FLOW WILL BRING S WINDS OF 15-20 KT TO THOSE WATERS THROUGH MON BEFORE DIMINISHING TO 10-15 KT MON NIGHT. SEAS OVER THE FAR WESTERN GULF SHOULD BUILD TO 3-5 FT...THEN SUBSIDE TO 2-3 FT MON NIGHT. OTHERWISE...LITTLE OVERALL CHANGE IS EXPECTED WITH WINDS AND SEAS ACROSS THE REMAINDER OF THE GULF DURING THE FORECAST PERIOD. SW N ATLC S OF 31N W OF 65W... THE 18 UTC PRELIMINARY SURFACE ANALYSIS SHOWS A TROUGH FROM EXTENDING FROM 30N78W TO ACROSS THE NW AND CENTRAL BAHAMAS. VISIBLE SATELLITE IMAGERY FROM EARLY THIS AFTERNOON AND NW DOPPLER RADAR FROM MELBOURNE FLORIDA INDICATE THAT A POSSIBLE LOW TO MID LEVEL CYCLONIC CIRCULATION IS ALONG THE TROUGH NEAR 28N77W. SCATTERED SHOWERS AND TSTMS WITH POSSIBLE GUSTY WINDS ARE CONFINED TO WITHIN 180 NM E AND 60 NM W OF THE TROUGH AXIS. A NEALY STATIONARY 1026 MB HIGH CENTER N OF THE AREA NEAR 33N61W EXTENDS A WEAK RIDGE SW TO THE SE BAHAMAS. BUOY OBSERVATIONS FROM ACROSS THE AREA SHOW NE-E 15 KT WINDS S AND SE OF THE RIDGE...S TO SW WINDS OF 5-10 KT SW OF THE RIDGE AND LIGHT AND VARIABLE WINDS OVER THE NW PORTION TO THE NW OF THE RIDGE. SEAS RANGE FROM 4-6 FT N OF 22N E OF THE BAHAMAS...TO 6-8 FT IN N SWELL S OF 22N E OF BAHAMAS...TO LOWER SEAS OF 1-3 FT W OF THE BAHAMAS...AND ALSO N OF 27N W OF 78W. THE TROUGH IS EXPECTED LIFT N OF THE AREA BY SUN NIGHT. TROPICAL STORM OPHELIA SE OF THE AREA IN FAR EASTERN TROPICAL N ATLC NEAR 17.8N 56.0W AT 1500 UTC THIS MORNING IS FORECAST TO TRACK NW THROUGH SUN NIGHT REACHING NEAR 21.6N 61.8W BY MON MORNING...THEN TURN MORE TO THE N AS IT REACHES TO NEAR 23.3N 63.1W TUE MORNING...AND CONTINUE NWD TO JUST E OF THE AREA WED AND THU. OPHELIA IS FORECAST TO REMAIN A MINIMAL TROPICAL STORM AS IT STAYS E OF THE AREA WITH THE TROPICAL STORM FORCE WIND RADII STAYING JUST E OF 65W. HOWEVER...WINDS AND SEAS ARE FORECAST TO INCREASE OVER THE FAR SE AND EASTERN SECTIONS OF THE AREA THROUGH THE THU BASED ON THIS TRACK...AND ON OPHELIA HOLDING TOGETHER AS A TROPICAL CYCLONE. THE GFS MODEL WEAKENS THE CYCLONE OVER THE FAR SE WATERS WED INTO EARLY THU. SO BASED ON THIS THE WAVEWATCH GUIDANCE HAS VERY LOW SEAS DURING THOSE TIMES...SO I WILL BE CLOSELY LEANING TOWARDS THE UKMET WAVEWATCH GUIDANCE CLOSELY FOR DAYS 3-5 WHERE IT KEEPS A CYCLONE IN TACT...WHEREAS THE REGULAR WAVEWATCH MODEL SHARPLY DIMINISHES THE SEAS AS DEPICTED BY A DYING SYSTEM IN THE GFS. IN ADDITION THE PROBABILITY GUIDANCE OF SEAS EXCEEDING 8 FT OR 12 FT AS ADVERTISED IN THE WW3 ENSEMBLES WITH THE FNMOC WAVE MODEL ENSEMBLE DROPS SEAS OFF DRAMATICALLY FROM THE EARLY TO MIDDLE PART OF NEXT WEEK DUE TO THE GUIDANCE ASSUMING OPHELIA FADES AWAY. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... THE MAIN FEATURE CONTINUES TO BE TROPICAL STORM OPHELIA NEAR 17.8N 56.0W AT 24/1500 UTC MOVING NW AT 11 KT. MAXIMUM SUSTAINED WIND 45 GUSTS TO 55 KT. OPHELIA IS FORECAST TO MOVE NW ACROSS THE THE N CENTRAL PORTION OF THE TROPICAL N ATLC AND TO THE NE OF THE LEEWARDS ISLANDS THROUGH LATE MON NIGHT AS PER LATEST NHC ADVISORY VALID 1500 UTC. IT IS FORECAST TO FLUCTUATE VERY LITTLE IN INTENSITY AS IT REACHES NEAR 18.8N 57.4W EARLY TONIGHT... ...NEAR 19.9N 59.1W SUN MORNING...TO 20.9N 60.7W BY EARLY SUN NIGHT...TO 21.6N 61.8W MON MORNING AND TO JUST NW OF THE TROPICAL N ATLC ZONE NEAR 23.3N 63.1W BY TUE MORNING. EXPECTED MAIN ISSUES WITH WINDS AND SEAS WILL BE CONFINED TO THE NORTHERN PORTIONS OF THE TROPICAL N ATLC ZONE THROUGH THIS PERIOD. EXPECT LINGERING MIXED N AND E SWELLS TO BE CONFINED TO THE FAR NW PORTION BY MON NIGHT. RECENT OBSERVATIONS FROM BUOYS 41101 AT 15N56W AND BUOY 41040 AT 14N53W SHOW S-SE WINDS OF 10-15 KT WITH SEAS OF 7-9 FT IN A N SWELL. THESE SEAS WILL SUBSIDE THROUGH SUN. A TROPICAL WAVE CURRENTLY E OF THE AREA ALONG 39N FROM 12N TO 19N IS MOVING W AT 10-15 KT. THE WAVE IS EXPECTED TO REACH TO NEAR 51W TUE MORNING...AND ENTER THE FAR EASTERN TROPICAL N ATLC WED MORNING. ONLY A SUBTLE SHIFT OF LIGHT WINDS IS EXPECTED WITH THE WAVE AS IT ENTERS THE ZONE. WARNINGS... GULF OF MEXICO... .NONE. CARIBBEAN SEA AND TROPICAL N ATLC... .AMZ087...TROPICAL STORM WARNING N OF 17N... SW N ATLC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER AGUIRRE