000 AGXX40 KNHC 121812 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 215 PM EDT THU JUN 12 2008 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO...THE GRADIENT BETWEEN LOW PRES LIFTING OUT THE ROCKIES INTO THE HIGH PLAINS AND A WEAK LOW-LEVEL RIDGING NOSING WWD ALONG THE NORTHERN GULF COAST HAS RESULTED IN A NARROW STRIPE OF SE 20 KT WINDS ACROSS PARTS OF THE CENTRAL AND WESTERN GULF...WITH MOST OF THE 20 KT WINDS WITHIN 120 NM EITHER SIDE OF A LINE FROM 21N90W TO 28N95W. NOAA BUOY 42002...IN THE MIDDLE OF THIS AREA...HAS SEEN SE WINDS INCREASE FROM 15 KT THIS MORNING TO 20 TO 25 KT AT PRESENT. WITHIN THIS REGION SEAS HAVE BUILT TO 4 TO 7 FT...THOUGH THERE IS SOME CHANCE THAT SOME SPOTTY 8 FT SEAS LIE FROM 22N AND 25N BETWEEN 90W AND 93W. OVER THE FAR SW GULF...E TO SE WINDS ARE LIGHTER...BLOWING AT 10 TO 15 KT. AND SEAS RANGE FROM 3 TO 5 FT. CLOSER TO THE RIDGE AXIS OVER THE N CENTRAL AND NE GULF...BUOY AND SHIP DATA SHOW E TO SE WINDS OF 10 KT OR LESS...WITH LOW WAVE HEIGHTS TO MATCH OF ABOUT 1 TO 3 FT. OF FINAL NOTE...SATELLITE IMAGERY INDICATES SCATTERED CONVECTION HAS DEVELOPED FROM THE SW INTO THE CENTRAL GULF ...LIKELY IN ASSOCIATION WITH THE NORTHERN END OF A TROPICAL WAVE INTERACTING WITH A MID- TO UPPER-LEVEL CYCLONIC CIRCULATION NEAR 24N92W. IN THE SHORT-TERM...MODELS SHOW LOW PRES LIFTING OUT OF THE PLAINS...WHICH SHOULD CAUSE THE ENHANCED GRADIENT AND RELATED SE WINDS ACROSS THE GULF TO DECREASE FRI MORNING AND AFTERNOON. SEAS OF 5 TO 8 FT NOW SHOULD FOLLOW SUIT AND SUBSIDE TO 3 TO 5 FT FRI NIGHT. WEAK HIGH PRES SHOULD THEN TAKE HOLD OVER THE CENTRAL AND WESTERN GULF THIS WEEKEND...WHICH SHOULD PROVIDE FOR A VERY LIGHT WIND REGIME. SEAS SHOULD RESPOND BY DROPPING TO 2 FT OR LESS NEARLY ALL AREAS BY SUN...EXCEPT NEAR THE YUCATAN WHERE UP TO 3 OR 4 FT SEAS ARE POSSIBLE. THEREAFTER...MODELS ALL AGREE ON A PATTERN CHANGE OVER THE EASTERN STATES...AS THE PERSISTENT FLAT MID-LEVEL RIDGE OVER THE SOUTHEAST FADES AWAY AND GIVES WAY TO LOW AMPLITUDE TROUGH. DESPITE THE EXPECTED TRANSITION...LITTLE CHANGE IN WINDS AND SEAS IS EXPECTED OVER THE GULF. MODELS DO SUGGEST THAT WEAK LOW PRES COULD FORM OVER THE NE GULF OR SERN STATES SUN INTO MON...AHEAD OF A COLD FRONT WHICH SHOULD DESCEND TO THE NORTHERN GULF COAST BY LATE TUE. THE EXPECTED PATTERN SUPPORTS INCREASING RAIN CHANCES ACROSS THE REGION...ESPECIALLY FL ON SUN AND MON AND THEN MUCH OF THE NORTHERN GULF AND ADJACENT LAND AREAS BY TUE. IN ADDITION...MODELS SHOW ANOTHER MIDDLE TO UPPER TROPOSPHERIC CUT-OFF LOW OVER THE CENTRAL AND SW GULF EARLY NEXT WEEK...WHICH SHOULD ALSO ENHANCE CONVECTION OVER THE REMAINDER OF THE AREA. WIND-WISE...EXPECT E TO SE WINDS OF 10 KT OR LESS OVER THE SRN GULF WITH SEAS OF 2 FT OR LESS AND SW TO W WINDS OF 10 KT OR LESS OVER THE NRN HALF OF THE GULF WITH SEAS OF 2 FT OR LESS. SW ATLC...WEAK SFC RIDGING ALONG 29-30N EXTENDING FROM E OF THE AREA INTO THE NRN WATERS OF THE SW ATLC SHOULD CHANGE LITTLE THROUGH TONIGHT. NEAR AND S OF THE RIDGE AXIS A GENERAL NE TO E WIND FLOW OF 10 TO 15 KT PREVAILS...WITH MORE VARIABLE WINDS OVER THE NRN WATERS AT SPEEDS OF 10 KT OR LESS. SEAS RANGE FROM 2 TO 3 FT OVER THE NRN WATERS AND 2 TO 4 FT S OF 26N...WITH THE NE FLOW MAKING IT W OF THE BAHAMAS. IN THE SHORT-TERM...A DEEP CLOSED-CYCLONE FORMING ALONG 60W WILL INTRODUCE A COLD FRONT TO THE N CENTRAL AND NE WATERS LATE FRI AND SAT. DESPITE THIS INTERRUPTION TO THE PATTERN...LITTLE CHANGE TO THE LOW-LEVEL WINDS AND SEAS ARE EXPECTED GOING INTO THE WEEKEND. THERE ARE TWO EXCEPTIONS TO THIS. OVER THE FAR NE BEHIND THE FRONT...NE SWELL PROPAGATING OUT OF THE N CENTRAL ATLC SHOULD BEGIN ARRIVING...WHICH SHOULD RESULT IN A SUBTLE RISE IN SEAS TO 4 TO POSSIBLY 7 FT OVER THE FAR NE. THE OTHER EXCEPTION COULD BE OVER THE FAR SOUTHERN WATERS S OF 22N...WHERE THE NRN END OF THE TROPICAL WAVE NOW APPROACHING THE WINDWARD ISLANDS COULD INFLUENCE WINDS AND SEAS. WITH THE GFS SHOWING THIS POSSIBILITY...HAVE INDICATED SLIGHTLY MORE UNSETTLED MARINE CONDITIONS OVER THIS AREA. LONGER TERM...MODELS HERALD A PATTERN CHANGE LATE THIS WEEKEND INTO EARLY NEXT WEEK. INSTEAD OF FLAT AND NARROW RIDGING ALONG THE GULF COAST AND SW ATLC...HEIGHTS SHOULD FALL AS A LOW AMPLITUDE TROUGH FORMS NEAR BUT JUST INLAND FROM THE E COAST. MEANWHILE...A STRONGER LOW-LEVEL SUBTROPICAL RIDGE IS FORECAST TO PUSH INTO THE ERN WATERS MON AND TUE. IN THE END...THERE ARE THREE IMPORTANT THEMES TO THE EXTENDED-RANGE. ONE IS THAT NE SWELL COMING OUT OF THE CTRL ATLC WILL CONTINUE PROPAGATING INTO THE ERN WATERS AND KEEP SEAS IN THE 4 TO 6 FT RANGE INTO MON AND TUE. THE SECOND NOTE IS THAT THE RE-EMERGENCE OF AN ENHANCED SUBTROPICAL RIDGE ALONG 25N SHOULD LEAD TO AN INCREASE IN SELY TRADES OVER THE SE WATERS MON AND TUE. THIRDLY...A COLD FRONT IS EXPECTED TO PUSH THROUGH THE SERN STATES TUE NEXT WEEK. WITH THE RIDGE AXIS ANYWHERE BETWEEN 24N AND 26N...EXPECT LOW-LEVEL SWLY FLOW FROM THE NE FL COAST EWD TO BEGIN INCREASING SOMETIME TUE...POSSIBLY REACHING 20 TO 25 KT AHEAD OF THE FRONT. SEAS SHOULD RESPOND BY BUILDING TO 4 TO 7 FT...WITH THE LATEST WAVEWATCH III RUN INDICATING UP TO 8 TO 9 FT SEAS POSSIBLE. CARIBBEAN AND TRPCL N ATLC...A TRPCL WAVE ALONG 66W HAS LOST SOME STEAM SINCE YESTERDAY...WITH VERY LITTLE HINT OF IT IN CONVENTIONAL FIELDS. ON THE OTHER HAND...THE TRPCL WAVE BEHIND IT ALONG 55W THIS MORNING IS BETTER-DEFINED...WITH SATELLITE IMAGERY SHOWING SCATTERED CONVECTION NEAR AND E OF ITS AXIS AND AN EARLIER QUIKSCAT PASS SHOWING A WIDE AREA OF 20 KT WINDS S OF 15N. IN THE END...SEVERAL OF THE LAST FEW GFS RUNS SHOW THE FIRST WAVE FADING AWAY WHILE THE SECOND WAVE BECOMES MORE DOMINANT. FOR THIS PACKAGE...THE GFS VERSION OF EVENTS IS ASSUMED WHICH MEANS THAT THE SECOND WAVE SHOULD REMAIN A DISTINGUISHABLE FEATURE THROUGH AT LEAST THE FIRST HALF OF THE PERIOD. IN THE SHORTER...EXPECT THE WIDESPREAD AREA OF NE TO E 20 KT WINDS OVER THE SRN TRPCL N ATLC TO SPREAD INTO THE ERN AND THEN CTRL CARIBBEAN SEA FRI AND SAT. NOAA WAVEWATCH III INDICATES A GENERAL INCREASE IN SEAS TO ABOUT 5 TO 8 FT IN THE ERN CARIBBEAN IN THE WAKE OF THE SECOND WAVE...WHILE NE TO E 20 TO 25 KT WINDS BLOW OVER THE CENTRAL CARIBBEAN AHEAD OF IT. OF NOTE...IF THIS FEATURE BECOMES MORE DIFFUSE WITH TIME...ITS IMPACT ON MARINE CONDITIONS COULD BE LESS THAN INDICATED HERE. WHILE MARINE CONDITIONS REMAIN UNSETTLED E OF 75W...NE WINDS OF 10 KT OR LESS SHOULD PREVAIL OVER THE NW CARIBBEAN THIS WEEKEND AND 10 TO 15 KT OVER THE SW CARIBBEAN. THIS SHOULD RESULT IN SEAS OF 3 FT OR LESS OVER THE NW...4 TO 7 FT S OF 18N BETWEEN 75W AND 85W. LONG-TERM...GLOBAL MODELS SHOW THE SUBTROPICAL RIDGE IN THE ATLC STRENGTHENING MON AND TUE...WITH THE 1016-LINE S OF SAN JUAN FOR THE FIRST TIME IN A WHILE. WITH THE ENHANCED RIDGE WILL COME FRESH TO STRONG TRADES. THE GFS INDICATES 20 TO 25 KT WINDS OVER A LARGE AREA GENERALLY W OF 67W...WITH UP TO 30 KT WINDS NEAR THE COAST OF COLOMBIA. SEAS SHOULD BUILD TO 6 TO 9 FT IN E SWELL EXCEPT 7 TO 11 FT NEAR THE COAST OF COLOMBIA. ELSEWHERE...NE TO E WINDS OF 20 KT SHOULD BLOW E OF 67W...WITH SEAS BUILDING TO 5 TO 8 FT. NE TO E SWELL FROM THE ERN/CTRL CARIBBEAN SHOULD PROPAGATE INTO THE SW CARIBBEAN BY TUE. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. .FORECASTER KIMBERLAIN. TROPICAL PREDICTION CENTER.