000 AGXX40 KNHC 121809 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 209 PM EDT FRI JUN 12 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 12Z GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST. FOR WAVE PARAMETERS BLENDED 12Z WW3 WITH PREVIOUS OFFICIAL FORECAST. MEDIUM CONFIDENCE. AN UPPER LEVEL LOW IS CENTERED NEAR 25N88W...WITH AN ASSOCIATED SURFACE TROUGH EXTENDING FROM 26N90W TO 19N93W. SCATTERED SHOWERS AND TSTMS ARE NOTED NEAR THE NORTHERN PORTION OF THE TROUGHING FROM 23N-29N BETWEEN 89W-94W. SHIP AND BUOY OBSERVATIONS ALONG WITH RECENT ASCAT SATELLITE PASSES INDICATE GENERALLY MODERATE TO FRESH SE FLOW ACROSS THE CENTRAL AND WESTERN GULF WATERS...WITH SLIGHTLY HIGHER WINDS NOTED IN THE VICINITY OF THE ONGOING CONVECTIVE ACTIVITY. THIS REMAINS SLIGHTLY BELOW THE 06 AND 12Z UTC GFS INITIALIZATION. SIMILARLY THE MWW3 INITIALIZED WITH SEAS TO 8 FT IN THE CENTER OF THE GULF...BUT NEARBY SHIP AND BUOY OBSERVATIONS AND AN EARLIER ALTIMETER PASS SUGGEST THAT MAY BE SLIGHTLY HIGH. THE MAIN INFLUENCES ON THE BASIN REMAIN THE ATLC RIDGE BUILDING WEST INTO THE EASTERN GULF...AND T.S. CARLOS OFF THE PACIFIC COAST OF MEXICO. THE RESULTING TIGHT GRADIENT IS SUPPORTING ENHANCED SE FLOW INTO THE S CENTRAL GULF WITH RELATED BUILDING SEAS. WHILE THERE REMAINS GOOD AGREEMENT AMONG MAJOR MODELS SHOWING THE GENERAL PATTERN...THE LATEST RUNS OF THE GFS REMAINS STRONGER AND SOMEWHAT LESS CONSISTENT THAN THE ECMWF OR UKMET WITH REGARD TO THE MARINE FORECAST CONDITIONS. THIS PROBLEM CONTINUES INTO EARLY NEXT WEEK WHEN ALL MAJOR MODELS INDICATE A WEAK LOW OR TROUGH FORMING OVER NORTHERN CENTRAL AMERICA AND SOUTHERN MEXICO THEN DRIFTING NW INTO THE SW GULF OF MEXICO IN CLOSE PROXIMITY TO THE MEXICAN COAST. THIS WILL ENHANCE GRADIENT FLOW AGAIN OVER THE CENTRAL GULF. THE GFS HAS BACKED OFF GALE FORCE WINDS OFF YUCATAN BY EARLY NEXT WEEK BUT STILL SHOW 30 KT WINDS BY LATE SUN INTO MONDAY AS THE TROUGH EMERGES INTO THE SW GULF. GIVEN THE INITIALIZATION OF THE GFS...THE OFFICIAL FORECAST FAVORS THE SLIGHTLY MORE CONSERVATIVE ECMWF INTO EARLY NEXT WEEK WHICH IS CLOSE TO THE GFS ON TIMING AND PLACEMENT BUT SLIGHTLY WEAKER ON GRADIENT FLOW. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: FOR WINDS 12Z GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST. FOR WAVE PARAMETERS BLENDED 12Z MWW3 INTO PREVIOUS OFFICIAL FORECAST. HIGH CONFIDENCE THEN MEDIUM CONFIDENCE BY SUNDAY. BUILDING ATLC HIGH PRES N OF THE AREA ALONG WITH THE PASSAGE OF A COUPLE OF TROPICAL WAVES ARE SUPPORTING STRONG TRADES OVER THE S CENTRAL CARIBBEAN THIS AFTERNOON. RECENT BUOY...SHIP OBS...AND RECENT ASCAT SCATTEROMETER PASSES DEPICT THESE WINDS...WITH BUOY OBS AND RECENT ALTIMETER PASSES INDICATING SEAS TO 9-10 FT OFF COLOMBIA IN THE STRONG TRADES. THESE SEAS ARE EXPECTED TO BUILD TO 11 OR 12 FT BY TONIGHT AS THE STRONG FLOW PERSISTS. FRESH TO STRONG WINDS ARE LIKELY ALSO OCCURRING OFF THE BELIZE AND THE CARIBBEAN COAST OF MEXICO AS WELL AS BETWEEN THE HIGH PRES AND LOWER PRES FARTHER WEST IN THE PACIFIC RELATED TO T.S. CARLOS. FARTHER EAST...A LONG FETCH OF FRESH TRADE WINDS IS SUPPORTING SEAS BUILDING TO A 8-9 FT RANGE ACROSS THE TROPICAL N ATLC S OF 15N AS NOTED IN BUOY OBSERVATIONS AND ALTIMETER DATA. THIS PATTERN WILL PERSIST THROUGH EARLY NEXT WEEK. THE MAIN FORECAST CHALLENGE REMAINS THE POTENTIAL FOR A LOW OR TROUGH TO DEVELOP OVER NORTHERN CENTRAL AMERICA BY SUNDAY...ENHANCING THE GRADIENT OVER THE NW CARIBBEAN. THE 12 UTC GFS INDICATES WINDS TO GALE WARNING FORCE SUNDAY AS A RESULT. THE ECMWF SHOWS A SIMILAR PATTERN BUT REMAINS SLIGHTLY WEAKER...AND THE OFFICIAL FORECAST IS A BLEND OF THE ECMWF AND GFS FOR THE NW CARIBBEAN SUNDAY THROUGH EARLY NEXT WEEK. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: FOR WINDS 12Z GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST. FOR WAVE PARAMETERS BLENDED 12Z MWW3. HIGH CONFIDENCE. THE ATLC RIDGE IS ESTABLISHED ALONG ROUGHLY 29N/30N MAINTAINING GENERALLY LIGHT TO GENTLE BREEZES N OF 25N...AND MODERATE TO FRESH TRADES S OF 25N...WITH STRONG WINDS PULSING N OF HISPANIOLA AT NIGHT. A WEAK FRONTAL BOUNDARY MOVING EAST OFF THE CAROLINAS WILL TEMPORARILY WEAKEN THE WESTERN PORTIONS OF THE RIDGE N THE BAHAMAS LATE SAT INTO SUN...THEN LIFT NE OF THE AREA. THE FORECAST WILL MAINTAIN GOOD CONSISTENCY WITH THE PREVIOUS ONE AS LITTLE CHANGES ARE EXPECTED TO IMPACT THE BASIN THROUGH EARLY NEXT WEEK. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 HUFFMAN. NATIONAL HURRICANE CENTER.