000 AGXX40 KNHC 211746 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1246 PM EST WED JAN 21 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: ECMWF BLENDED WITH GFS AND PREVIOUS OFFICIAL FORECAST. TAFB NWPS USED FOR WAVE HEIGHTS. MED CONFIDENCE. A SURFACE TROUGH REACHING FROM APALACHICOLA TO 25N87W WILL SHIFT E AHEAD OF A COLD FRONT DRIFTING INTO THE NW GULF. THE FRONT EXTENDS FROM THE TEXAS COAST THROUGH SOUTHERN LOUISIANA AND NE TOWARD THE CAROLINAS...AND WILL SHIFT SOUTHWARD INTO THE NORTHERN GULF LATE TODAY BEFORE STALLING OVERNIGHT. PATCHY FOG...WITH VISIBILITIES 1 NM OR LESS...ARE NOTED OVER PORTIONS OF THE TEXAS COASTAL WATERS THIS MORNING ALONG THE FRONT. THIS IS EXPECTED TO BURN OFF BY MID DAY. THE MAIN FORECAST ISSUE THROUGH THE REMAINDER OF THE WEEK WILL BE THE DEVELOPMENT AND TRACK OF LOW PRES ACROSS THE NORTHERN GULF AND A TRAILING COLD FRONT SWEEPING THE GULF. THE DRIVER FOR THIS IS A SHARP UPPER TROUGH CURRENTLY OVER THE FOUR CORNERS AREA EXPECTED TO MOVE EASTWARD INTO THE SOUTHERN PLAINS THU AND FRI...AND INTO THE MISSISSIPPI VALLEY SAT AND SUN. THE OPERATIONAL GFS REMAINS WEAKER THAN THE GFS ENSEMBLE...ECMWF...UKMET AND SREF WITH REGARD TO THE LOW PRES. BLENDING THE SLIGHTLY MORE AGGRESSIVE ECMWF WITH THE GFS AND PREVIOUS FORECAST WILL IMPART PLACEMENT OF THE LOW PRES OVER NE MEXICO EARLY THU...THEN SHIFT THE LOW INTO THE N CENTRAL GULF COAST NEAR MOBILE BAY BY EARLY FRI. A STRONG TRAILING FRONT WILL SWEEP THE GULF FRI AND SAT. THE GFS IS UNUSUALLY WEAKER THAN THE ENSEMBLE GFS WITH REGARD TO MINIMAL GALE WARNINGS OFF TAMAULIPAS FRI. THE SREF SHOWS MINIMAL PROBABILITIES FOR GALE WARNING OFF NE MEXICO...BUT A BETTER CHANCE FARTHER SOUTH OF VERACRUZ...WHICH IS MORE CLIMATOLOGICALLY SENSIBLEGIVEN THE STRENGTH OF THE HIGH PRES BEHIND THE FRONT. THE OFFICIAL FORECAST NOW CALLS FOR SUSTAINED MINIMAL GALE WARNINGS OFF VERACRUZ FRI. GALE WARNINGS MAY BE REQUIRED AS WELL FOR THE NW AND W CENTRAL GULF LATE THU INTO FRI FOR FREQUENT GUSTS TO GALE WARNING FORCE AS COOLER AIR EMERGES OVER THE GULF. STRONG NORTHERLY FLOW FOLLOWING THE FRONT WILL DIMINISH STARTING SAT AS HIGH PRES BUILDS BEHIND THE FRONT. LOOKING AHEAD TO EARLY NEXT WEEK...THE GFS AND ECWMF ADVERTISE A BACKDOOR FRONT SAGGING INTO THE NE GULF LATE MON. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST. TAFB NWPS USED FOR WAVE HEIGHTS. MED-HIGH CONFIDENCE. AN EARLIER RAPIDSCAT PASS INDICATED STRONG WINDS OFF COLOMBIA. OTHERWISE GENERALLY MODERATE TO FRESH TRADE WINDS PERSIST ACROSS THE BASIN. THE SUBTROPICAL RIDGE N OF THE AREA WILL REMAIN WEAKENED THROUGH FRI DUE TO A SERIES OF UPPER TROUGHS AND AN ASSOCIATED LOW PRES AREA MIGRATING FROM THE GULF INTO THE WESTERN ATLC. THIS WILL MAINTAIN THE RELATIVELY SUBDUED TRADE WIND PATTERN IN THE CARIBBEAN...WITH ONLY LOCALIZED OVERNIGHT ENHANCEMENT OFF COLOMBIA AND THE GULF OF HONDURAS. A RELATED COLD FRONT WILL MOVE THROUGH THE YUCATAN CHANNEL AND INTO THE FAR NW CARIBBEAN SAT AND SUN FOLLOWED BY STRONG NORTHERLY FLOW. THE FRONT WILL WEAKEN AS IT CONTINUES SOUTHWARD...REACHING FROM EASTERN CUBA TO EASTERN HONDURAS BY EARLY NEXT WEEK. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST. TAFB NWPS USED FOR WAVE HEIGHTS. MED-HIGH CONFIDENCE. A MID LEVEL SHORT WAVE TROUGH MOVING OFF THE CAROLINAS IS SETTING OFF A SERIES OF THUNDERSTORM WARNINGS OVER THE WATERS N OF THE BAHAMAS MOVING RAPIDLY EASTWARD. AN ASSOCIATED SURFACE TROUGH REACHING FROM 31N76W THROUGH THE NORTHERN BAHAMAS TO THE CAY SAL AREA WILL SHIFT EASTWARD AS WELL...ERODING THE WESTERN EXTENT OF THE SUBTROPICAL RIDGE CURRENTLY ANCHORED BY 1020 MB HIGH PRES CENTERED NEAR 31N65W. A FRONT WILL MOVE OFF THE SE GEORGIA COAST LATE TODAY AND REACH FROM 31N70W TO THE NORTHERN BAHAMAS THEN STATIONARY TO NEAR W PALM BEACH BY EARLY THU. THE ZONAL FLOW ALOFT WILL NOT ALLOW THE FRONT MUCH FARTHER PENETRATION SOUTHWARD THROUGH THU...WITH THE NORTHERN PORTION OF THE FRONT BREAKING AWAY AND CONTINUING EASTWARD. THE PORTION OVER FLORIDA AND THE FAR WESTERN ATLC WATERS WILL LIFT NORTHWARD AS A WARM FROM BY EARLY FRI AHEAD OF LOW PRES MOVING FROM THE GULF INTO THE SOUTHEAST UNITED STATES. SOUTHERLY WINDS WILL INCREASE AHEAD OF THE LOW PRES FRI N OF THE BAHAMAS W OF 75W. THE LOW WILL SHIFT INTO THE CAROLINAS BY EARLY SAT. THE MAIN FORECAST QUESTION AT THAT TIME WILL BE THE POTENTIAL FOR GALE WARNING FORCE SOUTHERLY FLOW N OF 30N AHEAD OF THE ASSOCIATED FRONT PUSHING OFF THE NE FLORIDA COAST. THE LATEST OPERATIONAL GFS INDICATES THIS...AND THE SREF SHOWS 5 TO 10 PERCENT CHANCE FOR GALE WARNINGS. WILL HOLD OFF ON MENTIONING GALE WARNINGS FOR NOW BUT WILL RETAIN WINDS TO 30 KT N OF 30N AHEAD OF THE FRONT SAT AND SAT NIGHT WITH SEAS TO 13 FT. THE FRONT WILL SHIFT EASTWARD AND REACH FROM 28N65W THROUGH THE SOUTHERN BAHAMAS BY LATE SUN WITH WINDS AND SEAS DIMINISHING. LOOKING AHEAD...ANOTHER LOW PRES AREA WILL MOVE ACROSS THE CAROLINAS EARLY NEXT WEEK WITH ANOTHER FRONT MOVING INTO THE WATERS N OF 25N ACCOMPANIED BY STRONG WESTERLY FLOW. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... .GMZ023...SW GULF S OF 22N W OF 94W... GALE CONDITIONS POSSIBLE FRI INTO FRI NIGHT. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 CHRISTENSEN. NATIONAL HURRICANE CENTER.