000 AGXX40 KNHC 100645 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 245 AM EDT FRI OCT 10 2014 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: 00Z GFS AND 12Z ECMWF BLENDED WITH PREVIOUS FORECAST. NWPS USED FOR WAVES. HIGH CONFIDENCE. 1018 MB HIGH PRESSURE LINGERS IN THE FAR NE GULF NEAR APALACHEE BAY WITH A RIDGE AXIS EXTENDING SW-W TO THE CENTRAL TEXAS COAST. LATEST IN-SITU AND REMOTE SENSED OBSERVATIONS DEPICT LIGHT WINDS AND 1-2 FT SEAS IN THE NE GULF...WITH MODERATE TO LOCALLY FRESH WINDS AND 3-5 FT SEAS ELSEWHERE IN THE BASIN. LITTLE CHANGE IN THE WEATHER PATTERN AND MARINE CONDITIONS IS EXPECTED THROUGH SUN NIGHT. A COLD FRONT WILL BE MOVING THROUGH THE TEXAS HILL COUNTRY BY EARLY MON MORNING...PUSHING INTO THE NW GULF COASTAL WATERS BY LATE MON AFTERNOON/EARLY EVENING...THEN QUICKLY EXTENDING FROM NEAR MOBILE BAY TO THE SW GULF TUE MORNING...AND THEN FROM NEAR APALACHEE BAY TO 18N94W TUE EVENING. THE 00Z GFS AND 12Z ECMWF ARE VERY SIMILAR WITH RESPECT TO THE TIMING/LOCATION OF THE FRONT AND BOTH HAVE WINDS UP TO 40 KT IN ZONE GMZ023/SW GULF TUE AFTERNOON INTO TUE NIGHT. THE GFS ALSO HAS GALE FORCE WINDS IN THE W CENTRAL GULF/GMZ017 TUE MORNING WHILE THE ECMWF SHOWS 30 KT. THE GEFS 34 KT PROBABILITIES ARE ONLY 10 PERCENT FOR GMZ023. WILL CONTINUE TO HEADLINE GALE CONDITIONS POSSIBLE FOR THE SW GULF WHICH MAY NEED TO BE EXTENDED TO THE N. FRESH TO STRONG WINDS ARE EXPECTED ELSEWHERE BEHIND THE FRONT WITH SEAS BUILDING TO AT LEAST 12 FT IN THE SW GULF. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: 00Z GFS AND 12Z ECMWF BLENDED WITH PREVIOUS FORECAST. NWPS USED FOR WAVES. HIGH CONFIDENCE. AN ILL-DEFINED TROPICAL WAVE IS MOVING FROM THE CENTRAL TO W CARIBBEAN...CURRENTLY ALONG 77W S OF 19N. ANOTHER TROPICAL WAVE IS MOVING THROUGH THE TROPICAL N ATLC AND WILL MOVE ACROSS THE LEEWARD ISLANDS TONIGHT THROUGH EARLY SAT...THEN WEAKENING AND BECOMING HARDER TO TRACK WHILE CONTINUING WESTWARD. LATEST IN- SITU AND REMOTE SENSED OBSERVATIONS INDICATE MAINLY LIGHT TRADES AND 1-3 FT SEAS E OF 76W (EXCEPT TO 20 KT NEAR THE WINDWARD PASSAGE)...WITH MODERATE TO LOCALLY FRESH TRADES AND 3-6 FT SEAS W OF 76W. THE ONLY SIGNIFICANT CONVECTION IS IN THE W CARIBBEAN FROM 11N TO 17N W OF 80W UNDER UPPER LEVEL DIFFLUENCE ON THE NW SIDE OF AN UPPER ANTICYCLONE LOCATED NEAR 14N80W. LITTLE CHANGE IN MARINE CONDITIONS IS EXPECTED THROUGH SUN. THE PRESSURE GRADIENT IS FORECAST TO TIGHTEN SUN NIGHT THROUGH MON ACROSS THE CENTRAL CARIBBEAN IN THE WAKE OF THE SECOND TROPICAL WAVE AND AS HIGH PRESSURE LOCATED WELL TO THE N OVER THE CAROLINAS ALSO NOSES A RIDGE DOWN TO THE SE IN THE SW N ATLC. THIS WILL INCREASE TRADES TO FRESH LEVELS IN THE CENTRAL CARIBBEAN WHICH WILL BUILD SEAS TO 6-7 FT. WINDS AND SEAS WILL THEN DIMINISH/SUBSIDE TUE AND TUE NIGHT AS THE PRESSURE GRADIENT WEAKENS. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: 00Z GFS AND 12Z ECMWF BLENDED WITH PREVIOUS FORECAST. NWPS USED FOR WAVES. MEDIUM CONFIDENCE THROUGH SUN...THEN LOW CONFIDENCE. A WEAK BACK DOOR COLD FRONT IS DISSIPATING N OF 30N W OF 76W AS 1020 MB HIGH PRES LOCATED NEAR THE NORTH CAROLINA OUTER BANKS EXTENDS A RIDGE TO THE S-SW. LATEST IN-SITU AND REMOTE SENSED OBSERVATIONS SHOW MODERATE TO FRESH NE-E WINDS ACROSS THE WATERS W OF 65W...ALONG WITH 4-7 FT SEAS E OF 70W...3-5 FT BETWEEN 70W AND 77W AND 1-3 FT W OF 77W. RIDGING WILL PERSIST W OF 70W THROUGH SUN WITH LITTLE CHANGE IN MARINE CONDITIONS OTHER THAN DIMINISHING WINDS. THE RIDING WILL CHANGE ORIENTATION AND SHIFT TO THE E SUN NIGHT THROUGH EARLY NEXT WEEK AS A COLD FRONT MOVES INTO THE SE U.S. MODERATE TO FRESH RETURN FLOW WILL DOMINATE THE WATERS W OF 70W DURING THIS TIME PERIOD WITH THE FRONT APPROACHING THE SE GEORGIA/NE FLORIDA COASTAL WATERS TUE NIGHT. 1006 MB LOW PRES NEAR 23N62W CONTINUES TO MOVE TO THE NNW AT AROUND 9 KT. VERY ACTIVE CONVECTION IS PRESENT BETWEEN 90 NM AND 300 NM IN THE NE SEMICIRCLE OF LOW. RECENT ASCAT AND ASCAT-B SCATTEROMETER PASSES SHOWED NEAR GALE FORCE WINDS IN THIS AREA AS WELL AND A 05Z ALTIMETER PASS INDICATED SEAS UP TO 13 FT...2 FT HIGHER THAN MWW3 GUIDANCE. THE 00Z GFS IS SLOWER WITH THE MOVEMENT OF THE LOW AND MORE TO THE RIGHT COMPARED TO THE 12Z ECMWF WHICH TAKES THE LOW TO 65W BY 00Z TONIGHT...WITH THE ECMWF THEN QUICKLY TAKING THE LOW TO 30N65.5W BY 00Z SUN WHILE THE GFS STILL HAS THE LOW NEAR 27N65W BY THEN. A BLEND OF THESE 2 SOLUTIONS WAS USED FOR THE LATEST GRIDDED PACKAGE. THIS LOW HAS A HIGH POTENTIAL FOR TROPICAL OR SUBTROPICAL CYCLONE DEVELOPMENT DURING THE NEXT 48 HOURS. THE WORST OF THE ASSOCIATED CONDITIONS WILL LIKELY REMAIN E OF THE OFFSHORE WATERS...HOWEVER FRESH TO STRONG N-NE WINDS ON THE W SIDE OF THE LOW AND BUILDING SEAS WILL STILL MANAGE TO IMPACT THE WATERS E OF 70W. MEANWHILE...A TROPICAL WAVE WELL SE OF THE SW N ATLC IS EXPECTED TO MOVE W-NW DURING THE NEXT SEVERAL DAYS. THE GFS...ECMWF AND UKMET ALL SHOW LOW PRES DEVELOPING ALONG IT WHILE SIGNIFICANT DIFFERENCES IN THE SPEED AND TRACK EXIST. THIS FEATURE MAY IMPACT THE SE ZONES TUE INTO WED. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... .GMZ023...SW GULF S OF 22N W OF 94W... GALE CONDITIONS POSSIBLE TUE INTO TUE NIGHT. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 LEWITSKY. NATIONAL HURRICANE CENTER.