000 AGXX40 KNHC 110742 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 342 AM EDT THU JUN 11 2015 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: FOR WINDS ECMWF BLENDED WITH PREVIOUS OFFICIAL FORECAST. FOR WAVE PARAMETERS BLENDED 00Z TAFB NWPS WITH PREVIOUS OFFICIAL FORECAST. MEDIUM CONFIDENCE. A 0230 UTC ASCAT SATELLITE PASS INDICATED SE WINDS OVER THE S CENTRAL GULF JUST N OF THE YUCATAN CHANNEL ARE STARTING TO INCREASE. THIS IS IN RESPONSE TO A TIGHTENING PRESSURE GRADIENT BETWEEN THE ATLC RIDGE BUILD INTO THE EASTERN GULF...AND A DEVELOPING TROPICAL CYCLONE OFF THE PACIFIC COAST OF MEXICO. WHILE MODELS GENERALLY AGREE ON THE OVERALL PATTERN...THE GFS CONTINUES TO SHOW RUN TO RUN INCONSISTENCIES CONCERNING THE STRENGTH AND TRACK OF THE DEVELOPING LOW PRES IN THE PACIFIC WHICH IS IMPACTS THE GULF OF MEXICO FORECAST. THIS IS ESPECIALLY TRUE BY SAT WHEN THE GFS DEVELOPS A LOW PRES AREA NW OF YUCATAN...APPEARING TO BE DOWNWIND SHEAR VORTICITY IN THE SW FLOW AND POSSIBLY AIDED BY A SHARP UPPER TROUGH DIGGING INTO TEXAS AND THE NW GULF AT THAT TIME. THE GFS IS FORECASTING GALE FORCE WINDS OFF NORTHERN YUCATAN AS A RESULT BY LATE SUN. THE OFFICIAL FORECAST CONTINUES TO FOLLOW THE MORE OF AN ECMWF SOLUTION ESPECIALLY BY SAT...ALTHOUGH ADJUSTMENTS WERE MADE TO INCREASE THE SW WINDS FRI INTO SAT OVER THE CENTRAL GULF WITH A NOD TO THE GFS AND TO MAINTAIN CONSISTENCIES WITH PREVIOUS FORECASTS. TAFB NWPS WAVE GUIDANCE INDICATES SEAS TO 8 FT OVER THE S CENTRAL GULF BY LATE TODAY...BUILDING TO 8 TO 11 FT EXPANDING NORTHWARD TO THE CENTRAL AND N CENTRAL GULF BY EARLY FRI IN THE STRONG SW FLOW. WINDS DIMINISH SLIGHTLY FRI AS THE RIDGE WEAKENS WHEN A WEAK FRONT MOVES ACROSS THE SOUTHEAST U.S. THE RIDGE BUILDS WEST AGAIN SUN THROUGH EARLY NEXT WEEK...INCREASING SE FLOW SUN THROUGH EARLY NEXT WEEK OVER THE WESTERN GULF. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: FOR WINDS GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST. FOR WAVE PARAMETERS USED BLEND OF 00 UTC TAFB NWPS WAVE WITH PREVIOUS OFFICIAL FORECAST. HIGH CONFIDENCE. VARIOUS RECENT SHIP OBSERVATIONS...ALONG WITH A 0230 UTC ASCAT SATELLITE PASS AND A PAIR OF ALTIMETER PASS INDICATED 20 TO 25 KT SE WINDS WITH SEAS ALREADY UP TO 8 TO 11 FT OVER THE NW CARIBBEAN. IN ADDITION...THE SAME ASCAT PASS INDICATED 20 TO 25 KT TRADE WINDS OFF THE COASTS OF WESTERN VENEZUELA AND NE COLOMBIA. THE STRONGER WINDS ARE THE RESULT OF A TIGHT PRESSURE GRADIENT BETWEEN A BUILDING ATLC RIDGE TO THE N OF THE BASIN AND DEVELOPING TROPICAL CYCLONE OFF THE PACIFIC COAST OF MEXICO. THE WINDS AND SEAS OVER THE NW CARIBBEAN WILL DIMINISH SAT AS THE ATLC RIDGE WEAKENS...BUT THE RIDGE WILL BUILD AGAIN BY LATE SAT INTO SUN ALLOWING THE AREA OF STRONG TRADE WINDS TO EXPAND NORTH AND WESTWARD ACROSS THE ENTIRE CENTRAL CARIBBEAN AND INTO THE WESTERN CARIBBEAN...WITH STRONG WINDS PULSING MOSTLY OVERNIGHT AND EARLY MORNING IN THE FAR NW CARIBBEAN. WINDS WILL BE GOVERNED IN PART BY THE PASSAGE OF TROPICAL WAVES MOVING THROUGH THE REGION. THE FIRST WAVE IS CURRENTLY ENTERING THE EASTERN CARIBBEAN AND WILL MOVE INTO THE CENTRAL CARIBBEAN EARLY FRI...THROUGH THE CENTRAL CARIBBEAN AND INTO THE SW CARIBBEAN BY LATE SAT...AND SLOWLY THROUGH THE FAR SW CARIBBEAN AND INTO CENTRAL AMERICA SUN AND MON. A SECOND TROPICAL WAVE CURRENTLY NEAR 50W WILL APPROACH THE WINDWARD ISLANDS BY EARLY FRI...WITH SEAS BUILDING TO 8 FT IN THE WAKE OF THE TROPICAL WAVE IN THE TROPICAL N ATLC WATERS S OF 15N IN FRESH TRADES. THE WAVE WILL ENTER THE CENTRAL CARIBBEAN BY LATE SAT AND ACROSS THE SW CARIBBEAN SUN THROUGH TUE. A THIRD TROPICAL WAVE WILL PASS 55W LATE SAT...APPROACH THE WINDWARD ISLANDS BY LATE SUN ACCOMPANIED BY STRONG E WINDS...SEAS 8 TO 10 FT AND INCREASED SHOWERS AND TSTMS...BEFORE CROSSING THE EASTERN CARIBBEAN INTO THE CENTRAL CARIBBEAN EARLY NEXT WEEK. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: FOR WINDS GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST. FOR WAVE PARAMETERS USED AN EVEN BLEND OF TAFB NWPS WAVE PARAMETERS WITH PREVIOUS OFFICIAL FORECAST. HIGH CONFIDENCE. A WEAK SURFACE TROUGH EXTENDS FROM 30N56W TO A WEAK 1018 MB LOW AT 27N65W...WITH SCATTERED SHOWERS ALONG THE TROUGH. A RIDGE EXTENDS FROM THE 1018 MB HIGH SW TO NEAR 25N80W. THE LOW PRES AND TROUGH ARE TIED TO A AN UPPER LOW THAT IS LIFTING NE CURRENTLY...AND THESE SURFACE FEATURES ARE IN THE PROCESS OF BEING OVERTAKEN BY THE SUBTROPICAL RIDGE BUILDING INTO THE WESTERN ATLC FROM A 1024 MB HIGH PRES AREA CENTERED NEAR 29N42W. THE RIDGE WILL EXTEND WESTWARD ALONG ROUGHLY 28N BY LATE TODAY AND WILL BE THE MAIN WEATHER FEATURE THROUGH AT LEAST SUNDAY. A WEAK SURFACE TROUGH WILL MOVE WEST ALONG THE SOUTHERN PERIPHERY OF THE RIDGE THROUGH THE GREATER ANTILLES AND INTO THE SOUTHERN BAHAMAS FROM LATE TODAY THROUGH LATE SAT. A WEAK TROUGH OR FRONTAL BOUNDARY WILL MOVE OFF THE SOUTHEAST U.S. COAST LATE SAT AND SUN THEN SHIFT E OF BERMUDA AND STAY N OF 30N THROUGH EARLY NEXT WEEK. THIS WILL BRIEFLY WEAKEN THE RIDGE BUT OTHERWISE THE RIDGE WILL MAINTAIN GENERALLY LIGHT TO GENTLE BREEZES AND MINIMAL N OF 25N...ALTHOUGH WINDS AND SEAS MAY BE HIGHER NEAR SCATTERED THUNDERSTORMS NEAR THE FLORIDA COAST FRI INTO SAT. FARTHER SOUTH MODERATE TO FRESH TRADES WITH 4 TO 6 FT WILL PREVAIL E OF THE BAHAMAS AND PARTICULARLY S OF 22N...WITH STRONGER WINDS OFF THE N COAST OF HISPANIOLA OVERNIGHT TONIGHT...SAT NIGHT AND SUN NIGHT ATTRIBUTED IN PART TO PASSAGE OF TROPICAL WAVES IN THE CARIBBEAN. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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.HURRICANE WARNINGS.GOV/MARINE $$ .FORECASTER CHRISTENSEN. NATIONAL HURRICANE CENTER.