000 AGXX40 KNHC 300700 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 300 AM EDT SUN JUN 30 2013 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W...AND THE SW N ATLANTIC INCLUDING THE BAHAMAS. ...GULF OF MEXICO... MODEL PREFERENCE: PREVIOUS FORECAST BLENDED WITH LATEST GFS AND ECMWF. PREVIOUS FORECAST BLENDED WITH TAFB NWPS FOR WAVE HEIGHTS. HIGH CONFIDENCE. A RIDGE EXTENDS FROM THE STRAITS OF FLORIDA ALONG 23N TO THE COAST OF MEXICO NEAR 24N98W. THIS RIDGE HAS BEEN SHIFTED S RELATIVE TO ITS NORMAL POSITION OVER THE NORTHERN GULF DUE TO A BROAD DEEP LAYER TROUGH AMPLIFYING OVER THE MISSISSIPPI VALLEY. THIS IS MAINTAINING GENERALLY LIGHT WINDS AND 1 TO 3 FT SEAS ACROSS THE BASIN. THE EXCEPTION IS OVER THE FAR NE GULF WHERE DYNAMICS ALOFT ARE ENHANCING CLUSTERS OF CONVECTION AND MAINTAINING 10 TO 15 KT WINDS (15 TO 20 KT IN THE COASTAL WATERS) ALONG WITH WITH 2 TO 4 FT SEAS. A WEAK COLD FRONT ASSOCIATED WITH THE UPPER TROUGH HAS SHIFTED JUST OFFSHORE OF E TEXAS AND W LOUISIANA INTO THE NEARSHORE COASTAL WATERS. THE SUPPORTING UPPER PATTERN IS IN THE PROCESS OF STALLING AND WILL BECOME MORE BROAD EARLY NEXT WEEK... LEAVING LIGHT SW TO W WINDS ALOFT. AS THIS OCCURS THE FRONT WILL STALL LATER TODAY THROUGH MON...DISSIPATING ALTOGETHER BY MID WEEK. MEANWHILE THE NORTHERN PORTION OF A TROPICAL WAVE IN THE WESTERN CARIBBEAN WILL TRACK NW THROUGH THE NW CARIBBEAN AND YUCATAN PENINSULA AS A TROUGH THROUGH EARLY NEXT WEEK. GLOBAL MODELS INDICATE THE POTENTIAL FOR WEAK LOW PRES TO FORM IN THE FAR SW GULF BY MID WEEK. THE RIDGE CURRENTLY ALONG 23N/24N WILL LIFT BACK TO THE N THROUGH MID WEEK FOLLOWING THE DISSIPATION OF THE WEAK FRONT OVER THE NORTHERN GULF...AND AHEAD OF THE ADVANCING TROUGH EMERGING OUT OF YUCATAN. LIGHT WINDS AND SEAS WILL PREVAIL INTO MID WEEK. SE WINDS WILL INCREASE OVER THE S CENTRAL GULF BY LATE WED IN THE WAKE OF THE TROUGH/FORMER TROPICAL WAVE AND AS THE RIDGE SHIFTS N. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC... MODEL PREFERENCE: PREVIOUS FORECAST BLENDED WITH LATEST GFS AND ECMWF. PREVIOUS FORECAST BLENDED WITH TAFB NWPS FOR WAVE HEIGHTS. HIGH CONFIDENCE. OVERNIGHT/EARLY MORNING SCATTEROMETER DATA INDICATE THAT WINDS HAVE DIMINISHED TO MODERATE TO FRESH ACROSS THE BASIN AS RIDGING N OF THE REGION HAS WEAKENED ALLOWING FOR THE PRES GRADIENT TO RELAX SLIGHTLY. THE SOUTHERN PORTION OF A TROPICAL WAVE IS APPROACHING NICARAGUA AND HONDURAS WHILE THE NORTHERN PORTION CONTINUES OVER WATER INTO THE NW CARIBBEAN TOWARD THE GULF OF HONDURAS. A SECOND TROPICAL WAVE IS NOW IN THE E CARIBBEAN ALONG 64W/65W. THIS WAVE IS INTERACTING WITH AN UPPER LOW CENTERED WELL NE OF THE VIRGIN ISLANDS NEAR 25N61W...WITH AN UPPER TROUGH EXTENDING TO THE NW COAST OF VENEZUELA. THE POSITION OF THE UPPER TROUGH FRAMES THE AREAS OF CONVECTION OVER THE CARIBBEAN...WITH NEARLY CLOUD FREE SKIES OVER THE CARIBBEAN W OF THE SECOND TROPICAL WAVE TO 71W...WITH MODERATE TO STRONG CONVECTION ASSOCIATED WITH THE WESTERN TROPICAL WAVE BETWEEN 76W AND 83W. CONVECTION ASSOCIATED WITH THE EASTERN WAVE CONTINUES TO DIMINISH AS UPPER LEVEL WESTERLY SHEAR TAKES ITS TOLL ON THE WAVE. GLOBAL MODEL CONSENSUS SHOWS THE WESTERN WAVE LOSING DEFINITION AS IT DRIFTS W OVER THE NEXT SEVERAL DAYS...EVENTUALLY AS A TROUGH MOVING THROUGH THE YUCATAN PENINSULA EARLY NEXT WEEK. THE EASTERN WAVE WILL SIMILARLY DEAMPLIFY AS IT SHIFTS W ACROSS THE CARIBBEAN ...EVENTUALLY MERGING WITH THE WESTERN WAVE BY MID WEEK OVER CENTRAL AMERICA AND SOUTHERN MEXICO. TRADE WIND FLOW OVER THE S CENTRAL CARIBBEAN WILL START TO INCREASE BY MON NIGHT FOLLOWING THE PASSAGE OF THE SECOND WAVE. A THIRD TROPICAL WAVE WILL APPROACH THE SOUTHERN TROPICAL N ATLC WATERS BY THU. ...SW N ATLANTIC W OF 55W INCLUDING THE BAHAMAS... MODEL PREFERENCE: PREVIOUS FORECAST BLENDED WITH LATEST GFS AND ECMWF. PREVIOUS FORECAST BLENDED WITH WAVEWATCH FOR WAVE HEIGHTS. HIGH CONFIDENCE. AN ATLC RIDGE HAS SHIFTED NORTHWARD EXTENDING FROM A 1030 MB HIGH WELL NE OF THE REGION NEAR 29N43W TO THE SW THROUGH BERMUDA TO THE NORTHERN BAHAMAS...DISRUPTED BY A SURFACE TROUGH DRIFTING WESTWARD N OF 28N ALONG 55W. OVERNIGHT/EARLY MORNING SCATTEROMETER DATA INDICATES AN AREA OF FRESH S TO SW WINDS N OF 29N W OF 74W (FRESH TO STRONG N OF 31N)...BETWEEN THE RIDGE AND A DEEP LAYER TROUGH TO THE W. SEAS ARE GENERALLY 4 TO 6 FT OUTSIDE THE BAHAMAS...WITH UP TO 7 FT IN THE AREA OF STRONGER WINDS N OF 29N W OF 74W. CLUSTERS OF CONVECTION ARE NOTED OVER THE BAHAMAS AS WELL...ENHANCED BY A SHARP UPPER TROUGH CENTERED OVER NASSAU. OPERATIONAL MODELS SHOW THE TROUGH BECOMING LESS AMPLIFIED AND WEAKENING OVER THE NEXT COUPLE OF DAYS ALLOWING THE STRONGER WINDS IN THE NW PORTION OF THE BASIN TO DIMINISH WITH THE RIDGE CONTINUING TO SHIFT N. S OF 24N/23N...MODERATE TRADES WILL FRESHEN THROUGH MID WEEK AS A TROPICAL WAVE MOVES THROUGH THE CENTRAL CARIBBEAN. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... GMZ011...NONE. GMZ013...NONE. GMZ015...NONE. GMZ017...NONE. GMZ019...NONE. GMZ021...NONE. GMZ023...NONE. GMZ025...NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... AMZ011...NONE. AMZ013...NONE. AMZ015...NONE. AMZ017...NONE. AMZ019...NONE. AMZ021...NONE. AMZ023...NONE. AMZ025...NONE. AMZ027...NONE. AMZ029...NONE. AMZ031...NONE. AMZ033...NONE. AMZ035...NONE. AMZ037...NONE. AMZ039...NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... AMZ111...NONE. AMZ113...NONE. AMZ115...NONE. AMZ117...NONE. AMZ119...NONE. AMZ121...NONE. AMZ123...NONE. AMZ125...NONE. AMZ127...NONE. *FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT: HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT: HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP FOR ADDITIONAL INFORMATION PLEASE VISIT: HTTP://WWW.HURRICANES.GOV/MARINE $$ .FORECASTER LEWITSKY. NATIONAL HURRICANE CENTER.