000 AGXX40 KNHC 041847 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 247 PM EDT FRI SEP 4 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 INTO PREVIOUS OFFICIAL. FOR WAVEHEIGHTS USED BLEND OF TAFB NWPS AND MWW3 WITH FEW MINOR MANUAL EDITS. HIGH CONFIDENCE THROUGH DAY 2...THEN AVERAGE CONFIDENCE THEREAFTER. A MID LEVEL TROUGH EXTENDS SW FROM THE FL BIG BEND TO NEAR 25N94W. SCATTERED TSTMS ARE OBSERVED WITHIN 90 NM SE OF THE TROUGH BETWEEN 86W-90W. A 1016 MB HIGH CENTER IS ANALYZED AT 27N87W. LATEST BUOY OBSERVATIONS SHOW MAINLY GENTLE SE WINDS ACROSS THE GULF...EXCEPT FOR SW-W WINDS LIGHT TO MODERATE WINDS N OF 28N. THE OBSERVATIONS SHOW SEAS IN THE 1-2 FT RANGE... EXCEPT FOR 3-4 FT SEAS S OF 24N W OF 92W. THE TROUGH WILL CONTINUE TO MOVE SE THROUGH SAT NIGHT AS THE HIGH CENTER SHIFTS WESTWARD TO THE CENTRAL WATERS. A RIDGE WILL EXTEND FROM THE HIGH SE TO THE HE FL STRAITS...AND A RIDGE EXTENDING NW TO THE NE TX COAST. LITTLE CHANGE THEN EXPECTED THROUGH THE PERIOD MODELS SUGGEST THAT THE HIGH WILL SHIFT SE TO OVER THE FAR SW FL COAST WITH A RIDGE EXTENDING NW TO THE MS DELTA ON TUE AND INTO WED.. EXPECT LIGHT ANTICYCLONIC FLOW WITHIN ABOUT 300 NM OF THE RIDGE AXIS...WITH SOUTHERLY RETURN FLOW INCREASING TO 10- 15 KT ACROSS THE W-CENTRAL GULF DURING THE OVERNIGHT HOURS. AN INVERTED THERMAL TROUGH WILL DEVELOP EACH AFTERNOON OVER THE YUCATAN PENINSULA...AND THEN MOVE W-NW ACROSS THE SW GULF WATERS...GENERALLY TO THE S OF 22N BETWEEN 90-93W DURING THE EVENING THROUGH LATE NIGHT HOURS...REACHING ALONG 94-95W DURING THE EARLY DAYLIGHT HOURS...AND THEN DISSIPATING BY EARLY AFTERNOON. EXPECT THIS TROUGH TO BE ACCOMPANIED BY A NE-E 15-20 KT WIND SHIFT TONIGHT...THEN EXPECT ONLY 10-15 KT NOCTURNAL EVENTS THROUGH THE REMAINDER OF THE PERIOD. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: LATEST GFS BLENDED INTO PREVIOUS OFFICIAL. FOR WAVEHEIGHTS USED BLEND OF TAFB NWPS AND MWW3. HIGH CONFIDENCE. ATLC RIDGE N OF THE AREA COMBINED WITH LOW PRESSURE OVER NW COLOMBIA WILL CONTINUE TO ENHANCE FRESH TO LOCALLY STRONG NOCTURNAL TRADES WITHIN ABOUT 150 NM OF THE COLOMBIAN COAST AND ALSO ALONG THE FAR NW COAST OF VENEZUELA. NE-E SWELLS WILL GENERATE COMBINED SEAS OF 7-8 FT AS FAR W AS 13N78W ON SAT... THEN COMBINED SEAS OF 4-7 FT ARE EXPECTED DOWNSTREAM SUN-WED. A TROPICAL WAVE WAS ADDED TO THE 12 UTC SURFACE MAP OVER THE EASTERN CARIBBEAN ALONG 63W/64W BASED ON SATELLITE CLOUD SIGNATURE AND ON WIND/PRESSURE DATA FROM THE LESSER ANTILLES REPORTING SITES AND ALSO FROM DATA FROM BUOY 42060 AT 16N63W. THIS WAVE WILL MOVE ACROSS THE REST OF THE EASTERN CARIBBEAN THROUGH SAT MORNING...THE CENTRAL CARIBBEAN SAT NIGHT THROUGH SUN NIGHT AND THE WESTERN CARIBBEAN MON THROUGH TUE. A THIRD TROPICAL WAVE WILL PASS 55W THIS AFTERNOON...ENTER THE EASTERN CARIBBEAN EARLY SAT NIGHT...THEN REACH THE CENTRAL CARIBBEAN MON AND TUE AND WESTERN CARIBBEAN WED. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: LATEST GFS BLENDED INTO PREVIOUS OFFICIAL. FOR WAVEHEIGHTS USED BLEND OF TAFB NWPS AND MWW3. HIGH CONFIDENCE. THE 18 UTC PRELIMINARY SURFACE ANALYSIS HAS A WEAK RIDGE EXTENDING ROUGHLY ALONG 24N. A WEAK 1012 MB LOW IS LOCATED NEAR 30N77W WITH A TROUGH SW TO INLAND THE E CENTRAL FLORIDA COAST NEAR CAPE CANAVERAL. THE BUOY OBSERVATIONS ALONG WITH PARTIAL ASCAT DATA DEPICT GENERALLY GENTLE WINDS THROUGHOUT WITH DIRECTION SE-S S OF OF THE RIDGE AND SW-W N OF THE RIDGE. THE SEAS ARE IN THE 1-3 FT RANGE E OF THE BAHAMAS AND 1-2 FT W OF THE BAHAMAS. THE FORECAST WILL HAVE LITTLE IN THE WAY OF CHANGES FROM PREVIOUS ONES. THE RIDGE WILL RETREAT EASTWARD THROUGH EARLY ON SAT ALLOWING FOR THE 1012 MB LOW TO DROP SEWD TO NEAR 29N73W. THE LOW WILL THEN BE NUDGED NORTHWARD SUN AND MON AS A HIGH CENTER BECOMES ESTABLISHED NEAR THE NW BAHAMAS. THE LOW WILL LINGER OVER THE FAR NW PORTION AS IT WEAKENS TO A TROUGH MON AND TUE. WINDS AND SEAS WILL CHANGE LITTLE INTO NEXT WEEK...WITH THE ONLY EXCEPTION BEING BRIEF INSTANCES OF E 15-20 KT WINDS BETWEEN THE SE BAHAMAS AND HISPANIOLA. THE GFS...ECMWF AND UKMET ARE IN GOOD AGREEMENT THAT A FALL PATTERN SETS UP N OF THE AREA OVER THE WEEKEND SENDING A COLD FRONT SEWD CLIPPING THE FAR NE WATER WELL TO THE E OF THE FORECAST ZONES ON SUN AND MON WITH A TRAILING TROUGH PASSING ACROSS THE FAR NORTHERN PORTION OF ZONE 115 ONLY A 5-10 KT WIND SHIFT EXPECTED ALONG THIS BOUNDARY...HOWEVER SCT SHOWERS AND ISOLATED TSTMS ARE POSSIBLE WITH THE BOUNDARY. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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.