000 AGXX40 KNHC 251912 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 312 PM EDT THU APR 25 2013 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: 12 UTC GFS BLENDED INTO PREVIOUS OFFICIAL GRIDS WITH HIGH CONFIDENCE THROUGHOUT SURFACE ANALYSIS FROM LATE THIS MORNING AND INTO EARLY THIS AFTERNOON SHOW THAT THAT THE COLD FRONT THAT ENTERED THE GULF EARLY WED MORNING HAS REACHED A POSN FROM NE FLORIDA SW TO NEAR 27N90W WHERE IT BECOMES A WEAKENING STATIONARY FRONT TO 26N96W AND TO THE SW GULF NEAR 20N96W. HIGH PRES IS PRESENT ELSEWHERE ACROSS THE AREA. LATEST BUOY AND OIL PLATFORM OBSERVATIONS INDICATE NE WINDS OF 15-20 KT BEHIND THE FRONT...AND GENERALLY NE-E WINDS OF 10-15 KT ELSEWHERE. THE OBSERVATIONS SHOW SEAS IN THE RANGE OF 3-5 FT W OF ABOUT 91W EXCEPT SLIGHTER HIGHER SEAS OF 5-6 FT NEAR THE SRN TEXAS COAST PER BUOY 42020 AT 27N97W. SEAS E OF 91W ARE LOWER...IN THE 2-3 FT RANGE...AND LOWER SEAS OF 1-2 FT ARE NOTED IN THE NE PORTION. LATEST MODELS REMAIN IN VERY GOOD AGREEMENT WITH THE FORECAST THROUGH DAY 5 (TUE). WITH THE UPPER LEVEL TROUGH THAT SUPPORTED THE FRONT NOW HAVING LIFTED NE OF THE AREA AS BROAD SCALE MID/UPPER RIDGING BUILDS E ACROSS THE AREA IN ITS WAKE...THE COLD FRONT WILL UNDERGO A WEAKENING TREND AS IT PUSHES EWD ACROSS THE NE GULF AND FLORIDA PANHANDLE THROUGH THIS EVENING TO E OF THE AREA EARLY FRI. THE MAIN FEATURE TO TAKE PRECEDENCE ACROSS THE AREA WILL THEN BE HIGH PRES FROM THE U.S. E COAST THAT BUILDS SSW OVER MOST OF THE NRN AND CENTRAL PORTION TONIGHT THROUGH SAT AFTERNOON BEFORE WEAKENING INTO MON. A RATHER LIGHT PRES GRADEINT WILL PERSIST THROUGHOUT DURING THIS UPCOMING FORECAST PERIOD WITH LOW SEA STATE. THE CURRENT NE WINDS OF 15-20 KT BEHIND THE FRONT WILL DIMINISH TO 10-15 KT TONIGHT INTO FRI. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: 12 UTC GFS BLENDED INTO PREVIOUS OFFICIAL GRIDS WITH HIGH CONFIDENCE THROUGHOUT THE ASCAT PASS FROM 1442 UTC THIS MORNING SHOWED NE WINDS OF 10-15 KT ACROSS PORTIONS OF THE CENTRAL AND WRN CARIBBEAN...AND OVER MOST OF THE TROPICAL N ATLC ZONES. IN ADDITION...CURRENT AND RECENT BUOY REPORTS FROM THROUGHOUT THE MORNING AND EARLY AFTERNOON HAVE BEEN SHOWING THE SAME KIND OF WIND SPEEDS... WITH MORE OF CONCENTRATION OF NE 15 KT WINDS OVER THE SE PORTION OF THE TROPICAL N ATLC. THE BUOY OBSERVATIONS ALONG WITH A FEW SHIP REPORTS SHOW SEAS IN THE RANGE OF 5-7 FT IN THE SW PORTION OF THE CARIBBEAN...EXCEPT FOR A SMALL POCKET OF 6-8 FT IN ZONE 39 E OF ABOUT 77W. SEAS ELSEWHERE ARE IN THE RANGE OF 3-5 FT...EXCEPT LOWER SEAS OF 2-3 FT N OF 14N W OF JAMAICA...BETWEEN THE GREATER ANTILLES AND 17N AND ALSO OVER THE FAR NE AND E PORTIONS. ACROSS THE TROPICAL N ATLC SEAS OF 6-7 FT IN NE SWELLS ARE EVIDENT ACROSS THE NRN AND CENTRAL PORTIONS...WITH SEAS OF 5-6 FT IN THE SRN PORTION. LATEST MODEL RUNS ARE IN CONSENSUS WITH THE BROAD SCALE SYNOPTIC PATTERN N OF THE AREA NOT CAPABLE OF INDUCING DRASTIC CHANGES FROM WHAT IS CURRENTLY BEING OBSERVED. HIGH PRES N OF THE AREA WILL REMAIN WEAK AS WEAK TROUGHING N OF HISPANIOLA DRIFTS E THROUGH SUN. THIS WILL MAINTAIN A LIGHT PRES GRADIENT ACROSS THE REGION THROUGH TUE WITH ONLY SURGES OF NE 20 KT WINDS NEAR THE COAST OF COLOMBIA IN THE EVENINGS. A WEAK SURFACE TROUGH SE OF THE TROPICAL N ATLC WILL MOVE WNW AND ACROSS THE FAR SRN PORTION OF THE TROPICAL N ATLC FRI AFTERNOON...AND THROUGH LATE SUN BEFORE IT ENTERS THE FAR SE CARIBBEAN SEA AND CONTINUES THERE THROUGH MON BEFORE DAMPENING OUT LATE MON NIGHT INTO TUE. THIS TROUGH MAY INDUCE AN INCREASE OF SCATTERED SHOWERS AND TSTMS ACROSS THOSE WATERS. WINDS WILL VARY LITTLE OVER THE TROPICAL N ATLC INTO EARLY NEXT WEEK. THE MAIN FORECAST ISSUE IN THE SHORT AND MEDIUM PERIODS WILL BE QUITE AN EXTENSIVE BATCH OF LARGE LONG PERIOD NE SWELLS ORIGINATING FROM THE INDUCED TIGHT PRES GRADEINT BETWEEN A DEEP LAYER LOW OVER ERN ATLC NE OF OF THE FORECAST AREA AND STRONG HIGH PRES OVER THE CENTRAL PORTION OF THE ATLC BASIN. THE LEADING EDGE OF THESE SWELLS IS APPROACHING THE FAR NE PART OF THE TROPICAL N ATLC. THE SWELL TRAIN WILL CONTINUE TO PROPAGATE SW ACROSS THE TROPICAL N ATLC. BY SAT AFTERNOON AND EVENING THE SWELLS WILL COVER THE ENTIRE TROPICAL N ATLC WATERS. THESE SWELL WILL ALSO SPREAD INTO THE CARIBBEAN PASSAGES. COMBINED MAX SEAS ARE FORECAST BY WAVEWATCH GUIDANCE TO MAX OUT AT 12-13 FT FRI EVENING INTO SAT BEFORE GRADUALLY SUBSIDING TO 10-11 FT EARLY SUN...TO 9-10 FT LATE SUN INTO MON...AND TO 9 FT DURING MON AND TUE. SEAS TO 8 FT IN NE SWELLS SHOULD LINGER THROUGH NE CARIBBEAN PASSAGES TUE. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: 12 UTC GFS BLENDED INTO PREVIOUS OFFICIAL GRIDS ...EXCEPT FOR A BLEND OF THE GFS/ECMWF/UKMET THROUGH THE FIRST 48 HRS OVER THE WRN PORTION. HIGH CONFIDENCE THROUGHOUT A WEAKENING SURFACE TROUGH IS ANALYZED ROUGHLY ALONG 66W N OF 20N. THIS FEATURE WAS CAPTURED NICELY BY THE 1438 UTC ASCAT PASS FROM THIS MORNING. WEAKENING SCATTERED TSTMS ARE WITHIN 150 NM E OF THE TROUGH. ELSEWHERE...A 1024 MB HIGH CENTER IS ANALYZED AT 30N76W. HIGH PRES IS PRESENT ELSEWHERE E OF THE TROUGH. LATEST BUOY AND SHIP OBSERVATIONS SHOW GENERALLY LIGHT WIND CONDITIONS THROUGHOUT. SEAS ARE IN THE 5-7 FT RANGE IN NE SWELLS OVER THE AREA E OF THE BAHAMAS...AND 2-4 FT W OF THE BAHAMAS...EXCEPT 3-5 FT OVER PORTIONS OF THE WATERS BETWEEN THE BAHAMAS AND FLORIDA... ESPECIALLY IN THE GULF STREAM CURRENT. VERY LITTLE DIFFERENCES ARE NOTED IN THE MODELS WITH RESPECT TO THE FORECAST OF THE AFOREMENTIONED TROUGH. THE TROUGH WILL MOVE LITTLE TO THE E THROUGH FRI AFTERNOON...THEN BECOME STATIONARY THROUGH SUN BEFORE DISSIPATING LATE SUN THROUGH MON. THE COLD FRONT DESCRIBED ABOVE OVER THE GULF OF MEXICO WILL MOVE INTO THE FAR NW PORTION THIS EVENING PER CONSENSUS OF THE 12 UTC GFS/UKMET/ECMWF MODELS. WILL FOLLOW GUIDANCE OF THESE MODELS IN FORECASTING THE FRONT TO REACH A POSN NEAR 31N70W TO NE FLORIDA FRI WHERE IT WILL STALL AND DISSIPATE LATE FRI AS HIGH PRES BUILDS S OVER THE MOST OF THE WRN PORTION...THEN SLOWLY SLIDES E THROUGH TUE. WINDS BRIEFLY BECOME NE AT 20 KT N OF THE FRONT FRI INTO SAT BEFORE DIMINISHING TO 10-15 KT. .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... GMZ011...NONE. GMZ013...NONE. GMZ015...NONE. GMZ017...NONE. GMZ019...NONE. GMZ021...NONE. GMZ023...NONE. GMZ025...NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... AMZ011...NONE. AMZ013...NONE. AMZ015...NONE. AMZ017...NONE. AMZ019...NONE. AMZ021...NONE. AMZ023...NONE. AMZ025...NONE. AMZ027...NONE. AMZ029...NONE. AMZ031...NONE. AMZ033...NONE. AMZ035...NONE. AMZ037...NONE. AMZ039...NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... AMZ111...NONE. AMZ113...NONE. AMZ115...NONE. AMZ117...NONE. AMZ119...NONE. AMZ121...NONE. AMZ123...NONE. AMZ125...NONE. AMZ127...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.HURRICANES.GOV/MARINE $$ .FORECASTER AGUIRRE. NATIONAL HURRICANE CENTER.