000 AGXX40 KNHC 131900 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 300 PM EDT SUN SEP 13 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: LATEST GFS BLENDED WITH PREVIOUS OFFICIAL. NWPS BLENDED WITH PREVIOUS OFFICIAL FOR WAVES. HIGH CONFIDENCE. A RATHER PRONOUNCED LONGWAVE TROUGH EXTENDING FROM THE EASTERN U.S. SW TO THE N CENTRAL GULF SUPPORTS A SURFACE COLD FRONT THAT IS ANALYZED FROM N CENTRAL FLORIDA SW TO JUST NW OF TAMPA FLORIDA...AND SW TO NEAR 26N92W. A PRE-FRONTAL TROUGH EXTENDS FROM TAMPA BAY SW TO 27N85W. HIGH PRES RIDGING EXTENDS SW FROM A 1021 MB HIGH CENTERED OVER SOUTHERN MISSOURI TO THE NW GULF. LATEST SATELLITE IMAGERY SHOWS CLUSTERS OF MODERATE CONVECTION CONFINED TO THE SW GULF ZONE 23 AND OVER THE CENTRAL AND EASTERN SECTIONS OF ZONE 17. THIS ACTIVITY IS ASSOCIATED WITH A SURFACE TROUGH THAT EXTENDS FROM 26N97W TO 20N96W...AND IS ALSO UNDER A DIFFLUENT PATTERN ALOFT SITUATED BETWEEN THE BASE OF THE LONGWAVE TROUGH AND AN E TO W ORIENTED MID TO UPPER LEVEL ANTICYCLONE LOCATED OVER CENTRAL MEXICO. SATELLITE IMAGERY HINTS AT A POSSIBLE MID-LEVEL CIRCULATION ASSOCIATED WITH THIS CONVECTION NEAR 22N96W...AND A SURFACE LOW IS LIKELY TO SOON FORM ALONG THE TROUGH NEAR 22N AS HINTED IN THE GLOBAL MODEL FIELDS AND IN THE NAM MODEL. CURRENT BUOY AND OBSERVATIONS ARE REPORTING NE 10-15 KT WIND NW OF THE FRONT...WHILE THE HIGH ELEVATED OIL PLATFORMS IN THE N CENTRAL GULF ARE REPORTING SLIGHTER HIGHER WINDS OF 15-20 KT. E-SE 10-15 KT WINDS ARE BEING REPORTED BY BUOY 42055 IN THE SW GULF NEAR 22N94W. WINDS SE OF THE FRONT ARE S-SW 10-15 KT. THE BUOYS AND RECENT ALTIMETER DATA INDICATE THAT SEAS ARE IN THE 2-4 FT RANGE...EXCEPT FOR A POCKET OF 3-5 FT SEAS FROM 20N-27N W OF 92W. THE COLD FRONT WILL MOVE SLOWLY REACH FROM NEAR SARASOTA FLORIDA TO TAMPICO MEXICO EARLY TONIGHT...THEN WEAKEN AND BEGIN TO LIFT BACK N AS A WARM FRONT FROM NEAR CEDAR KEY TO BROWNSVILLE TEXAS BY MON NIGHT...AND DISSIPATE INTO EARLY ON TUE AS MODELS SUGGEST. THE AFOREMENTIONED TROUGH AND SOON TO DEVELOP OVER THE FAR WESTERN GULF IS FORECAST TO HAVE A LOW CHANGE OF DEVELOPING INTO A TROPICAL CYCLONE OVER THE NEXT 24-48 HOURS AS IT MEANDERS IN THE SAME GENERAL AREA BEFORE MOVING INLAND THE MEXICO COAST AND WEAKENING. STILL IT APPEARS...THAT THE NORTHERN END OF A TROPICAL WAVE...CURRENTLY OVER THE CENTRAL CARIBBEAN SEA...WILL PASS THROUGH THE STRAITS OF FLORIDA AND SE GULF MON NIGHT THROUGH TUE NIGHT...THROUGH THE SOUTHERN PORTION OF THE CENTRAL GULF AND YUCATAN PENINSULA WED AND ACROSS THE SW GULF THU WHILE WEAKENING. A TIGHT PRES GRADIENT BETWEEN THE WAVE AND ATLC HIGH PRESSURE RIDGING TO ITS NE SHOULD RESULT IN E-SE 15-20 KT WINDS BEHIND THE WAVE WITH SEAS IN THE 3-5 FT RANGE TUE NIGHT AND INTO THE WED PERIOD. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: 12Z GFS BLENDED WITH PREVIOUS OFFICIAL. NWPS BLENDED WITH PREVIOUS OFFICIAL FOR WAVES. HIGH CONFIDENCE THROUGH TUE....THEN MEDIUM CONFIDENCE. THE MAIN FEATURES ARE A TROPICAL WAVE ALONG 72W/73W MOVING W 15 KT...AND ATLC HIGH PRESSURE RIDGING TO THE N OF THE BASIN. THE 1422 UTC ASCAT PASS FROM THIS MORNING INDICATED A SMALL PATCH OF NE 20 KT WINDS ON THE E EDGE OF THE PASS NEAR THE COAST OF COLOMBIA. THE MODELS REMAIN IN RELATIVELY GOOD AGREEMENT ON THE RIDGING N OF THE AREA DRIVING THE TRADE WINDS THROUGH TUE. AFTER THIS TIME...THE FORECAST OF THE TRADES AGAIN CARRIES SOME UNCERTAINTY AS LATEST GUIDANCE IS NOT IN COMPLETE AGREEMENT. STILL PREFER THE GFS SOLN OVER THE ECMWF AND UKMET SOLNS AFTER THE TUE PERIOD AS IT SEEMS TO MORE ACCURATELY DEPICT THE SYNOPTIC SCALE PATTERN AND RESULTANT PRESSURE GRADIENT AS IT REACTS TO A POSSIBLE CYCLONE FEATURE WELL E OF THE AREA FORECAST TO MOVE WESTWARD AND THEN N LATE IN THE FORECAST PERIOD AND HIGH PRES OVER THE WESTERN ATLC. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS OFFICIAL. NWPS WITH SMALL PERCENTAGE OF MWW3 BLENDED WITH PREVIOUS OFFICIAL FOR WAVES. HIGH CONFIDENCE. THE 18 UTC PRELIMINARY ANALYSIS HAS A COLD FRONT ENTERING THE FAR NW PORTION FROM NEAR 31N79W SW TO INLAND FLORIDA COAST THE CAPE CANAVERAL AREA. HIGH PRES IS PRESENT ENE OF THE BAHAMAS...WHILE A SURFACE TROUGH THAT EVOLVED FROM A TROPICAL WAVE OVER THE CENTRAL CARIBBEAN EXTENDS FROM 22N67W TO 19N69W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 60 NM OF THE TROUGH...HOWEVER RECENT SATELLITE IMAGERY INDICATES THAT THIS ACTIVITY IS UNDERGOING A WEAKENING TREND. LATEST BUOY AND FEW SHIP OBSERVATIONS SHOW RATHER LOW SEAS...IN THE 1-3 RANGE THROUGHOUT. THE ASCAT PASS 1416 UTC ASCAT PASS REVEALED A SWATH OF SW 20-25 KT WINDS WITHIN ABOUT 240 NM E OF THE FRONT N OF 29N. SCATTERED SHOWERS AND TSTMS ARE WITHIN 240 NM SE OF THE FRONT. GUIDANCE IN PRETTY GOOD AGREEMENT THAT THE FRONT FRONT WILL CONTINUE SE TO A PSN FROM NEAR 31N76W TO THE VERO BEACH AND LAKE OKEECHOBEE AREA TONIGHT...THEN BEGIN TO WEAKEN AND STALL. THE FRONTAL BOUNDARY WILL THEN LIFT SLIGHTLY THROUGH TUE NIGHT WHILE DISSIPATING. THE TROUGH ALONG 22N67W 19N69W WILL REACH EASTERN CUBA MON BUT WILL BE RATHER ILL- DEFINED AS MOVES ACROSS CENTRAL CUBA DURING MON NIGHT. WITH FEATURES FORECAST TO REMAIN ON THE WEAK SIDE...THE PRESSURE GRADIENT WILL BE RATHER LIGHT OVER MUCH OF THE AREA THROUGH THE PERIOD WITH LITTLE CHANGES TO WIND AND SEAS. STRONGER HIGH PRESSURE WILL REMAIN N OF THE AREA. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 AGUIRRE. NATIONAL HURRICANE CENTER.