000 AGXX40 KNHC 101748 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 150 PM EDT TUE JUN 10 2008 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO...LATEST SFC ANALYSIS SHOWS A WEAK RIDGE AXIS EXTENDING FROM THE SW ATLC INTO THE GULF OF MEXICO BETWEEN 27-28N AND THE NORTHERN END OF A TROPICAL WAVE FROM THE WESTERN CARIBBEAN INTO THE SE WATERS. UNDER THE PRESENT PATTERN...LIGHT TO MODERATE WINDS ARE THE RULE ACROSS MOST OF THE REGION... EXCEPT FOR A SMALL AREA S OF 22N W OF 94W. A QUIKSCAT PASS OVER THIS REGION BETWEEN 11-12 UTC INDICATED WIDESPREAD SE 20 KT WINDS...BUT THESE SHOULD DIMINISH BY THIS AFTERNOON OR EVENING. ELSEWHERE...E TO SE WINDS OF 10 TO 15 KT COVER THE S CENTRAL GULF N OF THE YUCATAN WWD THROUGH THE SW GULF AND THEN NWD TO OFFSHORE THE TX COAST W OF 95W. SEAS RANGE FROM 3 TO 5 FT OVER THESE AREAS EXCEPT POSSIBLY TO 6 FT WITHIN ABOUT 90 NM RADIUS OF 22N95W. IN FACT...BUOY 42055 RECENTLY REPORTS COMBINED SEAS OF 6 FT. WAVE PERIODS RANGE FROM 5-6 SEC...INDICATING MOSTLY E TO SE WIND WAVES AND FAIRLY STEEP WAVES. OVER THE NE WATERS...A LIGHTER E TO SE WIND OF 10 KT OR LESS DOMINATES...EXCEPT S TO SW N OF 28N /N OF THE RIDGE AXIS/. SEAS RANGE FROM 1 TO 3 FT...WITH WAVE HEIGHTS LESS THAN A FT POSSIBLE ALONG THE FL W COAST. WAVE PERIODS RANGE FROM 4-5 SEC. BETWEEN NOW AND WED NIGHT THE FEATURE OF MOST INTEREST WILL LIKELY BE THE NORTHERN END OF A WELL-DEFINED TROPICAL WAVE CURRENTLY ALONG 83W...WHICH SHOULD TRACK ACROSS THE YUCATAN...S CENTRAL AND SW GULF/BAY OF CAMPECHE LATER TODAY AND WED. SCATTERED TO POSSIBLY NUMEROUS SHOWERS AND TSTMS SHOULD ACCOMPANY THIS FEATURE...MOST ENHANCED AROUND THE DIURNAL EARLY MORNING MAXIMUM. EXPECT LOCALLY HIGHER WINDS AND SEAS NEAR ACTIVE AND SUSTAINED CONVECTION. EXTENDED RANGE /WED NIGHT THROUGH SUN/...A DEEP CLOSED CYCLONE ROTATING FROM THE NW CONUS TO THE HIGH PLAINS WILL CAUSE DEEP LOW PRES TO AGAIN FORM ACROSS THE PLAIN STATES. AS THIS OCCURS...MODEL GUIDANCE SHOWS A SUBTLE BUT IMPORTANT INCREASE IN THE SE LOW-LEVEL FLOW OVER THE CENTRAL AND TO SOME EXTENT THE WESTERN GULF WATERS BEGINNING WED NIGHT AND LASTING THROUGH MIDDLE OR LATE FRI. THE GFS HAS BEEN CONSISTENT IN SHOWING THE STRONGEST WINDS...SUSTAINED AT 20 KT...LYING ABOUT 120 NM EITHER SIDE OF A LINE FROM 21N90W TO 28N95W. NOAA WAVEWATCH III OUTPUT SUGGESTS THAT SEAS SHOULD BUILD TO 5 TO 7 FT OVER THE SW AND W CENTRAL GULF THU...BUT THE FETCH AND THE DURATION OF THE WINDS SHOULD NOT BE LONG ENOUGH TO OBSERVE SEAS GREATER THAN THAT. IN FACT...THE ENSEMBLE WAVEWATCH GUIDANCE SHOWS LITTLE TO NO CHANCE OF 8 FT OR GREATER SEAS...THOUGH THERE IS A FAIRLY HIGH PROBABILITY OF 6 TO 7 FT SEAS WITHIN 60 NM EITHER SIDE OF A LINE FROM 22N92W TO 28N94W. PERIODS SHOULD RANGE FROM 5-6 SEC...WHICH MEANS THAT DOMINANT WAVES WILL BE STEEP WIND WAVES. LOW PRES SHOULD FIZZLE OUT OVER THE PLAINS LATE FRI...AND WEAK HIGH PRES SITTING NEAR 28-29N 90W SHOULD CONTROL THE WEATHER ACROSS THE GULF THROUGH THE WEEKEND. WIND-WHIPPED SEAS OF UP TO 7 FT SHOULD SUBSIDE TO 3 TO 4 FT ACROSS THE SW HALF OF THE GULF BY LATE SAT AND 2 TO 3 FT SUN. LIGHT AND SOMEWHAT VARIABLE WINDS SHOULD COVER THE REST OF THE GULF /WIND LESS THAN 10 KT/ WHICH SHOULD RESULT TO 2 FT OR LESS SEAS. THE ONLY CONCERN FOR MARINE INTEREST MIGHT BE A MID- TO UPPER-LEVEL SHORTWAVE TROUGH OVER THE SERN STATES LATE THIS WEEKEND. MOIST...LOW-LEVEL SWLY FLOW ACROSS THE NE GULF AND AN UNSTABLE ATMOSPHERE SHOULD LEAD TO SCATTERED TO POSSIBLY NUMEROUS TSTMS FROM THE FL PANHANDLE SE THROUGH THE FL PENINSULA AROUND THIS TIME. AS ALWAYS...EXPECT HIGHER WINDS AND SEAS NEAR ACTIVE CONVECTION. SW ATLC...AS HAS BEEN THE CASE FOR MUCH OF THIS LAST WEEK...A WEAK LOW-LEVEL RIDGE IS FORECAST TO LIE ALONG 29-30N THROUGH THU. THE WEAK WIND REGIME IS PRODUCING LOW WAVE HEIGHTS OF AROUND 2 FT WITHIN ABOUT 180 NM OF THE FL E COAST...WITH 3 TO 4 FT SEAS FARTHER E...N AND E OF THE BAHAMAS. IN FACT...BUOY 41010 NEAR 28.9N78.5W TYPIFIES MARINE CONDITIONS OFF THE FL COAST...WITH A WAVE HEIGHT JUST UNDER 2 FT WITH A DOMINANT WAVE PERIOD OF 9 SEC. BUOY 41026 NEAR 23.9N70.9W HAS LIGHT ESE WINDS OF 4 KT AND A WAVE HEIGHT OF 3.3 FT IN NE SWELL. SEAS OF 2 FT OR LESS ARE COMMON W OF THE BAHAMAS...WITH 2 TO 3 FT SEAS INTO THE STRAITS OF FLORIDA. EXPECT THE CURRENT PATTERN OF WEAK RIDGING OVER THE NORTHERN WATERS TO CONTINUE THROUGH THU. HOWEVER...A SHORTWAVE TROUGH CROSSING THE GREAT LAKES TODAY IS FORECAST TO MOVE ATOP FLAT SUBTROPICAL RIDGING TO THE S AND CRUISE THROUGH THE NORTHEAST WED AND EARLY THU. THEREAFTER...ALL MODELS SUGGEST THAT THE SHORTWAVE WILL DIG RATHER SHARPLY NEAR OR JUST W OF 60W... PRODUCING A LARGE BREAK IN THE ATLC SUBTROPICAL RIDGE BY EARLY FRI. MOST MODELS ALSO HAVE A COLD FRONT ACCOMPANYING THE DIGGING TROUGH...WHICH SHOULD PASS THROUGH THE N CENTRAL AND NE WATERS OF THE SW ATLC LATE FRI INTO SAT. THE ECMWF HAS CONSISTENTLY BEEN SLOWER TO DRAG THE FRONT SWD INTO THE NE QUARTER OF THE FORECAST AREA THAN THE GFS BUT HAS BEEN MORE VIGOROUS WITH THE FRONT. GIVEN ITS BETTER CONSISTENCY...HAVE TAILORED THE FCST TO LOOK MORE LIKE THE ECMWF. DESPITE THE INTERRUPTION TO THE STEADY SUMMERTIME PATTERN OVER THE SW ATLC OF THIS PAST WEEK...MODELS SHOW NO MORE THAN AN INITIAL NE TO E 10 TO 15 KT SURGE BEHIND THE FRONT WHICH SHOULD QUICKLY DIMINISH TO 10 KT OR LESS SAT. SEAS OF 2 TO 3 FT FRI SHOULD BUILD... HOWEVER...TO 4 TO 5 FT BY SAT NIGHT N OF 28N E OF 72W. THE NOAA WAVEWATCH III ENSEMBLE GUIDANCE INDICATES THE CHANCE OF 6 FT OR GREATER SEAS IN NE SWELL OVER THE NE WATERS TO BE ZERO...SO EXPECT NO MORE THAN A SUBTLE CHANGE TO THE PATTERN. ELSEWHERE...WINDS SHOULD AVERAGE E 10 KT OR LESS MOST AREAS EXCEPT SE N OF 27N W OF 75W BUT SHOULD BECOME MORE NE TO E ALL AREAS BY THE WEEKEND. THE NORTHERN END OF A WHAT A TROPICAL WAVE PUSHING THROUGH THE CARIBBEAN COULD POTENTIALLY AFFECT THE WATERS S OF 24N SAT AND SUN...BUT IT IS STILL NOT ENTIRELY CLEAR TO WHAT EXTENT. IN THE VERY LEAST...MODEL GUIDANCE IS INDICATING SOME INCREASE IN THE CHANCE FOR CONVECTION NEAR AND SE OF THE SE BAHAMAS/HISPANIOLA OVER THE WEEKEND. AT THIS POINT...THE CURRENT MARINE PACKAGE WILL SUGGEST A MARGINAL INCREASE IN WINDS AND SEAS OVER THIS AREA SAT AND SUN WITH A GOOD CHANCE OF SOME PRECIPITATION. TRPCL ATLC AND CARIBBEAN...ONLY FEATURES OF NOTE THIS PERIOD ARE TWO TROPICAL WAVES...ONE NOW OVER THE WESTERN CARIBBEAN ALONG 83W AND ANOTHER ALONG 53W...MOVING W 10 TO 15 KT. THE WAVE IN THE WESTERN CARIBBEAN APPEARS TO BE INTERACTING WITH A WEAKNESS OVER THE FL PENINSULA...WHICH HAS LED TO A SUBSTANTIAL INCREASE IN CLOUDS AND TSTMS GENERALLY W OF 80W TODAY. IN THE VICINITY OF THE STRONGER CONVECTION...NOAA BUOY 42056 NEAR 20N85W REPORTED SE 25 KT WINDS EARLIER THIS MORNING...AND WINDS NOW ARE STILL NEAR 20 KT. SEAS RANGE FROM 5-6 FT IN SE WIND WAVES...WHICH IS 2 TO 3 FT BELOW CURRENT WAVEWATCH GUIDANCE. IN GENERAL...EXPECT E TO SE 15 TO 20 KT WINDS W OF 83W IN ASSOCIATION WITH THE WAVE ...WITH HIGHER WINDS POSSIBLE NEAR ACTIVE CONVECTIVE AREAS. A QUIKSCAT PASS NEAR 12 UTC CONFIRMED CURRENT WINDS OF 15 TO 20 KT OVER A LARGE PART OF THE NW CARIBBEAN SEA EXCEPT FOR THE FAR SW. SEAS SHOULD GENERALLY AVERAGE BETWEEN 3 TO 5 FT BUT LOCALLY HIGHER SEAS OF UP TO 7 FT CANNOT BE RULED OUT...ESPECIALLY IN THE GULF OF HONDURAS. THE WAVE SHOULD BEGIN PUSHING W OF THE AREA LATER TOMORROW...WHICH SHOULD RESULT IN DIMINISHING WINDS AND SUBSIDING SEAS. OTHERWISE...MODERATE TO FRESH TRADES STILL PREVAIL OVER THE CENTRAL CARIBBEAN...GENERALLY BETWEEN 11N AND 16N BETWEEN 68W AND 80W. ALTHOUGH THERE IS NO CURRENT MICROWAVE DATA...WINDS OF UP TO 25 KT STILL SEEM LIKELY DIRECTLY OFFSHORE THE COAST OF COLOMBIA. LITTLE CHANGE TO THIS PATTERN UNTIL OVER THE WEEKEND. APART FROM TROPICAL WAVE ACTIVITY...THE ATLC SUBTROPICAL RIDGE IS FORECAST TO BE WEAKER-THAN-NORMAL...WHICH SHOULD RESULT IN NE TO E WINDS OF 10 KT OR LESS OVER MOST AREAS W OF 80W BY LATE SAT OR SUN. ELSEWHERE...THE NEXT TROPICAL WAVE NOW ALONG 53W IS EXPECTED TO MOVE THROUGH THE WINDWARD ISLANDS WED AFTERNOON AND EVENING... REACHING 64W BY EARLY THU AND 70W BY FRI...76W BY SAT...AND 82W BY SUN. UNLIKE PREVIOUS TROPICAL WAVES...THIS ONE APPEARS AS IF IT WILL HAVE MORE UMPH TO IT. HOWEVER...IT SHOULD BE NOTED THAT THE GFS HAS BEEN AMPLIFYING THE WAVE AROUND 41W THE LAST SEVERAL RUNS INSTEAD OF THE WAVE AHEAD OF IT ALONG 53W. GIVEN THE RECENT SATELLITE APPEARANCE OF THE WAVE AT 53W...AM MORE INCLINED TO BELIEVE THAT IT WILL PRODUCE MORE OF AN IMPACT TO WINDS AND SEAS THAN THE ONE BEHIND IT ATTM. GIVEN THIS...HAVE INCREASED SE WINDS AND SEAS IN THE WAKE OF THE WAVE THROUGH THE PERIOD...WITH WAVEWATCH GUIDANCE SUGGESTING THAT SEAS COULD BUILD UP TO 6 TO 9 FT IN SE WIND WAVES S OF 15N E OF THE ISLANDS WED AND THU...WITH SIMILAR CONDITIONS ENTERING THE ERN CARIBBEAN THU AND FRI. WINDS SHOULD SLACKEN AND SEAS RELAX OVER THESE AREAS BY THE WEEKEND. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. .FORECASTER KIMBERLAIN. TROPICAL PREDICTION CENTER.