000 AGXX40 KNHC 141852 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 250 PM EDT THU MAY 14 2009 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... RETURN FLOW CONTINUES ACROSS THE GULF AROUND A SURFACE RIDGE N OF THE GULF EXTENDING WESTWARD FROM A SURFACE HIGH OVER THE CENTRAL ATLC. E TO SE WINDS OF 10 TO 15 KT PREVAIL ACROSS JUST ABOUT THE ENTIRE GULF AS NOTED BY BOTH BUOY OBSERVATIONS AND A QUIKSCAT PASS FROM JUST PAST 1200 UTC THIS MORNING. WINDS OVER THE FAR WESTERN GULF W OF ABOUT 95W ARE SE-S 15-20 KT AS REPORTED BY BUOYS THERE. AS A RESULT...WIND WAVES OF 4 TO 7 FT ARE OCCURRING IN THAT PART OF THE GULF WITH SEAS OF 3-5 FT IN THE SW PART AND 1 TO 3 FT ACROSS THE REMAINDER OF THE GULF. THIS GENERAL PATTEN OF WINDS AND SEAS IS FORECAST TO CONTINUE THROUGH SAT NIGHT WITH WINDS BECOMING MORE EASTERLY AS THE ATLC RIDGE TO THE NE EXTENDS W ACROSS THE NORTHERN GULF. RATHER BRISK E WINDS OF 20 TO POSSIBLY 25 KT CAN BE EXPECTED OVER THE FAR SE GULF NEAR THE STRAITS OF FL THROUGH SAT NIGHT. NE TO E WINDS OF 20-25 KT WILL ALSO OCCUR AROUND THE COAST OF YUCATAN THROUGH FRIDAY DURING THE EVENING HOURS THROUGH SAT NIGHT...DRIVEN BY VARIATIONS IN THE LOCAL TOPOGRAPHY OVER YUCATAN. GLOBAL MODEL GUIDANCE INDICATES AN OVERALL WEAKNESS IN THE SURFACE PRESSURE GRADIENT ACROSS THE GULF THIS WEEKEND IN RESPONSE TO THE APPROACH OF A SOUTHERN PLAINS COLD FRONT AND POSSIBLE LOW/TROUGH EMERGING FROM NEAR NW CUBA NWD TOWARDS THE VICINITY OF FLORIDA AS SUGGESTED BY THE GLOBAL MODELS. AS A RESULT...WIND SPEEDS AND SEA HEIGHTS WILL DECREASE THIS WEEKEND. WINDS WILL ALSO SHIFT TO N-NE AND INCREASE OVER JUST ABOUT THE ENTIRE GULF. PRESENT MODEL INDICATIONS ARE THAT THIS LOW WILL LIKELY FORM NEAR A SOUTHWESTWARD TRAILING MID-LEVEL TROUGH ASSOCIATED WITH THE AFOREMENTIONED FRONT EARLY MONDAY...AND GENERALLY TRACK IN A N OR NE DIRECTION. IT IS STILL TOO EARLY PINPOINT JUST HOW CLOSE TO THE GULF THIS FEATURE WILL BE NEAR THE GULF. THIS FEATURE MAY BE A HYBRID SUBTROPICAL/EXTRATROPICAL LOW OVER THE WESTERN ATLC AS OPPOSED TO THE GULF OF MEXICO. FORECAST CONFIDENCE IS CURRENTLY RATHER LOW IN THE PARTICULARS OF THIS SCENARIO...AND WILL CONTINUE TO BE MONITORED. CARIBBEAN... SURFACE HIGH PRESSURE N OF THE CARIBBEAN SEA IS MAINTAINING FRESH NE TO E TRADE WINDS ACROSS THE CARIBBEAN. A PARTIAL QUIKSCAT PASS FROM THIS MORNING SHOWED NE-E WINDS OF 10-15 KT ACROSS THE NW CARIBBEAN...WITH NE TO E WINDS OF 20-25 KT ACROSS THE FAR SOUTHERN WATERS NEAR THE COAST OF S AMERICA. ACROSS THE E CARIBBEAN BETWEEN 66W-75W E WINDS OF 15 TO 20 KT ARE NOTED. LATEST WAVEWATCH GUIDANCE INDICATES SEAS TO 8 FT NEAR THE COAST OF COLOMBIA...WITH SEAS OF 4 TO 7 FT ACROSS MUCH OF THE S CARIBBEAN. THIS PATTERN IS FORECAST TO PERSIST TO AROUND FRI NIGHT UNTIL A SUBTROPICAL SURFACE HIGH OVER THE CENTRAL ATLC MOVES EWD AND LOW PRES DEVELOPS OVER THE FAR WESTERN PORTION OF THE SW N ATLC. THIS WILL WEAKEN THE PRESSURE GRADIENT ACROSS THE CARIBBEAN...RESULTING IN TRADE WINDS DECREASING ACROSS THE ENTIRE CARIBBEAN BY SATURDAY...WITH WINDS GENERALLY LESS THAN 20 KT AND SEAS TO NO MORE THAN 6 FT BY SUNDAY AREAWIDE AND TO 5 FT BY TUE. SEAS WILL BE MUCH LOWER...IN THE 1-2 FT...OVER THE FAR WRN CARIBBEAN BY TUE. ATLANTIC S OF 31N W OF 55W... QUIKSCAT DATA FROM THIS MORNING SHOWED A WELL-DEFINED E-W SUBTROPICAL RIDGE OVER THE FAR NRN WATERS. E TRADE WINDS AT THE SOUTHERN PERIPHERY OF THIS SURFACE RIDGE ARE GENERALLY IN THE 15-20 KT RANGE ACROSS THE BAHAMAS...GREATER AND LESSER ANTILLES...AND THE TROPICAL N ATLC...WHERE SHIP OBSERVATIONS SHOW SEAS OF 6-7 FT. THE STRONGEST OF THESE WINDS ARE FOUND AROUND A SURFACE TROUGH OVER HISPANIOLA. THE SURFACE HIGH IS FORECAST TO MOVE EWD AS ITS ASSOCIATED UPPER LEVEL RIDGE TRANSLATES EASTWARD IN RESPONSE TO AN UPPER TROUGH CURRENTLY MOVING EASTWARD OVER THE W ATLC. A STATIONARY FRONT IS ALONG 28N65W 30N75W. THE FRONT IS FORECAST TO GRADUALLY DISSIPATE THROUGH TONIGHT W OF 70W AFTER SINKING SWD A LITTLE. NE TO E WINDS OF 15-20 KT ARE PRESENT NW OF THE FRONT N OF 30N BETWEEN 65W AND 73W...WITH SEAS UP TO 6 FT. SURFACE HIGH PRES N OF THE FRONT OVER THE W ATLC WILL INCREASE E TRADE WINDS TO 20-25 KT W OF THE BAHAMAS... PARTICULARLY OVER THE FLORIDA STRAITS FOR THU INTO SAT...WHERE SEAS WILL BUILD TO AROUND 9 FT. THE FRONT E OF 70W WILL STRENGTHEN AND MOVE SOUTHWARD INTO THE N TROPICAL ATLC BY THIS WEEKEND WITH N E-E WINDS OF 15-20 KT OVER THE NRN PORTION OF THE TROPICAL N ATLC THROUGH POSSIBLY SAT AFTERNOON WITH SEAS BUILDING UP TO 7 FT THROUGH MON...AND SUBSIDING TO 6 FT TUE. ATLC... .NONE. CARIBBEAN... .NONE. GULF OF MEXICO... .NONE. FORECASTER AGUIRRE. TROPICAL PREDICTION CENTER.