000 AGXX40 KNHC 181819 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 119 PM EST THU DEC 18 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: 12Z GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST. 12Z TAFB-NWPS USED FOR WAVE HEIGHTS. HIGH CONFIDENCE. 12Z SYNOPTIC ANALYSIS SHOWS A WEAKENING STATIONARY FRONT EXTENDING FROM NAPLES FLORIDA WSW TO 25N87W...THEN BECOMES A WARM FRONT NW TO GALVESTON BAY. THE WARM FRONT ATTACHES TO WEAK 1014 LOW PRESSURE ACROSS DEEP SOUTH TEXAS NEAR 27N98W. HIGH PRES IS BRIDGING EASTWARD ACROSS THE FRONT WITH RIDGE AXIS EXTENDING FROM THE MISSISSIPPI RIVER DELTA REGION SOUTHWARD THE YUCATAN PENINSULA. LATEST OBSERVATIONS AND SCATTEROMETER PASSES SHOW LIGHT ANTICYCLONIC FLOW ACROSS THE NORTHEASTERN THIRD OF THE BASIN... WHILE THE REMAINDER OF THE BASIN...GENERALLY LOCATED IN THE WARM SECTOR OF THE FRONTAL STRUCTURE...SHOWS GENTLE TO MODERATE S TO SE...TO MORE SOUTHERLY ACROSS THE FAR WESTERN GULF...WINDS S OF THE WARM FRONT. THE OBSERVATIONS SHOW SEAS IN THE 1-3 FT RANGE E OF 94W WITH SEAS SLIGHTLY HIGHER W OF 94W IN THE RANGE OF 3-5 FT WITHIN THE AREA OF STRONGEST RETURN FLOW. MODELS ARE IN GOOD AGREEMENT THAT THE WARM FRONT WILL LIFT N-NE ACROSS THE NORTHERN GULF COAST WATERS THROUGH FRI AS AN UPPER LEVEL TROUGH WITH AXIS EXTENDING FROM THE FOUR CORNERS REGION S TO THE CENTRAL BAJA CALIFORNIA PENINSULA APPROACHES FROM THE WEST. THE LOW PRESSURE WILL TRACK E-NE ALONG THE COASTAL PLAIN FROM NE TEXAS TO NEAR THE MOUTH OF THE MISSISSIPPI RIVER BY SAT. MODELS CONTINUE TO BE IN GOOD IN AGREEMENT WITH TRACK OF THE LOW AND WITH THE FORECAST POSITIONS OF THE ASSOCIATED COLD FRONT. THE COLD FRONT IS FORECAST TO EMERGE OFF THE TEXAS COAST AND MOVE ACROSS THE FAR WESTERN PORTION OF THE GULF BEGINNING FRI EVENING. BY SAT...AS THE LOW APPROACHES NEAR THE MOUTH OF THE MISSISSIPPI RIVER...THE FRONT WILL EXTEND FROM THERE SW TO NEAR TAMPICO... THEN BECOMING STATIONARY WHILE WEAKENING FROM THE FLORIDA BIG BEND SW TO THE EASTERN BAY OF CAMPECHE BY SUN. ANY REMNANTS OF THE BOUNDARY ARE EXPECTED TO EXTEND FROM NE FLORIDA TO THE NW TIP OF THE YUCATAN PENINSULA BY MON AS WEAK HIGH PRES BUILDS TO THE WEST. WITH RESPECT TO WINDS WEST OF THE FRONT...MODELS ARE IN GENERAL AGREEMENT WITH A BRIEF ONSET OF NORTHERLY 15-20 KT BEHIND THE FRONT OVER THE FAR WESTERN WATERS BORDERING THE COASTAL OFFSHORE WATERS FRI NIGHT INTO EARLY SAT AS THE PRES GRADIENT BETWEEN HIGH PRES BUILDING EASTWARD BEHIND THE FRONT AND THE AFOREMENTIONED LOW PRES IS CONDUCIVE FOR INITIATING SUCH WINDS. THESE WINDS THEN QUICKLY WEAKEN TO 10-15 KT SAT AFTERNOON AS THEY BEGIN TO SHIFT TO THE NE IN DIRECTION...AND WEAKEN SLIGHTLY TO 10 KT LATE SAT NIGHT INTO SUN. BY MON...MODERATE TO FRESH SOUTHERLY RETURN FLOW RE-ESTABLISHES ACROSS THE WESTERN GULF. SEAS IN THE WESTERN GULF BEHIND THE FRONT ARE EXPECTED TO BE IN THE 4-5 FT RANGE FRI NIGHT INTO SAT. SEAS SUBSIDE GRADUALLY TO 2-4 FT SUN. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: 12Z GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST. 12Z TAFB-NWPS USED FOR WAVE HEIGHTS. HIGH CONFIDENCE. 12Z SYNOPTIC ANALYSIS INDICATES A RIDGE...SLIGHTLY WEAKER THAN PREVIOUS DAYS...EXTENDING SE FROM THE YUCATAN PENINSULA TO NORTHERN NICARAGUA. EARLIER SCATTEROMETER DATA REVEALED A SWATH OF NE 20-25 KT WINDS SW OF CUBA TO 17N BETWEEN 77W-83W. A PORTION OF THE SAME SWATH OF THE SATELLITE INSTRUMENT SUGGESTED SIMILAR WINDS EXISTED ALONG AND WITHIN 120 NM OF THE COAST OF COLOMBIA. MODEL GUIDANCE ALONG WITH SURFACE ANALYSIS EXTRAPOLATION INDICATES THAT THESE WINDS WILL CONTINUE THROUGH THE EARLY OVERNIGHT PERIOD SW OF CUBA AND THROUGH THE FORECAST PERIOD NEAR THE COAST OF COLOMBIA...BUT IN A PULSING FASHION DURING THE OVERNIGHT AND EARLY MORNING HOURS WITH SEAS THERE BUILDING INTO A RANGE OF 8-10FT. ELSEWHERE ACROSS THE CARIBBEAN...BUOY AND ASCAT DATA ARE SHOWING MAINLY GENTLE TO MODERATE NE-E WINDS THROUGHOUT INCLUDING ACROSS THE FAR NORTHERN TROPICAL N ATLC WHERE A WEAKENING COLD FRONT EXTENDS FROM 17N55W TO GUADELOUPE THEN W TO NEAR 14N67W. SEAS ELSEWHERE IN THE CARIBBEAN ARE IN THE 3-5 FT RANGE...EXCEPT FOR LOWER SEAS OF 2-3 FT IN THE FAR EASTERN CARIBBEAN AND 5-7 FT SEAS IN THE SW CARIBBEAN NEAR THE COAST OF COLOMBIA. SEAS IN THE TROPICAL N ATLC ARE IN THE 5-6 FT RANGE IN A NE TO E SWELL COMPONENT PER CURRENT BUOY DATA AND RECENT ALTIMETER DATA. THESE SEAS WILL REMAIN IN THAT SIMILAR RANGE DURING THE PERIOD. ...SW N ATLANTIC S OF 31N W OF 55W INCLUDING THE BAHAMAS... MODEL PREFERENCE: 12Z GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST. 12Z TAFB-NWPS USED FOR WAVE HEIGHTS. HIGH CONFIDENCE. 12Z SYNOPTIC ANALYSIS SHOWS A 1021 MB HIGH CENTERED E OF THE DISCUSSION AREA NEAR 31N53W EXTENDING A RIDGE AXIS W-SW THROUGH 26N65W TO 25N75W. TO THE NORTH OF THIS RIDGE AXIS...A COLD FRONT EXTENDS FROM 31N64W TO THE NW BAHAMAS AND THEN WESTWARD STATIONARY TO NEAR PORT EVERGLADES. RECENT ASCAT PASSES IN THE VICINITY OF THE FRONT INDICATED GENERALLY GENTLE W-NW WINDS W OF THE FRONT AND GENTLE TO MODERATE S-SW WINDS WITHIN 120 NM E OF THE FRONT. BUOYS...SHIPS...AND RECENT ALTIMETER PASSES SHOWED SEAS IN THE RANGE OF 4-6 FT E OF THE BAHAMAS AND LOWER SEAS OF 1-3 FT SW OF THE BAHAMAS. THE COLD FRONT WILL CONTINUE TO WEAKEN AS IT REACHES FROM NEAR 28N65W TO 26N72W FRI...WITH ANY REMNANTS MOVING E OF THE AREA BY SAT. HIGH PRES WILL ONCE AGAIN BUILD ACROSS THE BASIN IN THE WAKE OF THE BOUNDARY SAT NIGHT...BUT SHIFT EASTWARD THROUGH SUN IN RESPONSE TO ANOTHER COLD FRONT THAT APPROACHES THE FAR NW CORNER OF THE AREA SAT LATE INTO EARLY SUN. GUIDANCE SUGGESTS THAT THE UPPER FLOW WILL NOT BE ADEQUATE ENOUGH TO ALLOW THIS NEXT COLD FRONT TO ADVANCE INTO THE FORECAST WATERS VERY FAR AS IT MOST LIKELY WILL BECOME STATIONARY QUICKLY...REMAINING RELATIVELY WEAK...ALONG 30N/31N THROUGH SUN NIGHT. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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.