000 AGXX40 KNHC 081713 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 113 PM EDT WED JUL 8 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 WHICH WAS A GFS/ECMWF BLEND. TAFB NWPS BLENDED WITH PREVIOUS OFFICIAL FOR SEAS HEIGHTS AND PRIMARY WAVE PERIOD. HIGH CONFIDENCE. AN INVERTED THERMAL TROUGH IS EXPECTED TO DEVELOP EACH AFTERNOON OVER THE YUCATAN PENINSULA...AND THEN MOVE WNW ACROSS THE GULF WATERS S OF 23N BETWEEN 90-94W DURING THE EVENING THROUGH LATE NIGHT HOURS...REACHING ALONG 95W DURING THE EARLY DAYLIGHT HOURS...AND THEN DISSIPATE BY EARLY AFTERNOON. GENERALLY EXPECT AN E-SE 20-25 KT WIND SHIFT WITHIN ABOUT 120 NM OF THE TROUGH AXIS THROUGH FRI NIGHT...THEN GUIDANCE SUGGESTS ONLY A 15-20 KT WIND SHIFT THROUGH MON. AN UPPER TROUGH EXTENDS SW FROM THE MS DELTA TO NEAR 18N96W WITH UPPER DIFFLUENCE OVER ITS E SEMICIRCLE PROVIDING FAVORABLE UPPER SUPPORT FOR ISOLATED RW/TS OVER THE E- CENTRAL GULF WATERS...AND THUS DENOTED IN WEATHER GRIDS FOR TODAY AND TONIGHT. OTHERWISE...AN E-W RIDGE EXTENDS ACROSS THE NORTHERN WATERS WITH A SURFACE HIGH EXPECTED TO INTERMITTENTLY DEVELOP OVER THE NE AND N-CENTRAL WATERS ALONG THE RIDGE THROUGH SAT. THE RIDGE WILL BECOME ORIENTATED FROM NE TX TO NEAR 26N84W ON SUN...WITH THE SURFACE HIGH THEN APPEARING OVER THE NW WATERS ALONG THE RIDGE. THE RIDGE IS EXPECTED TO SHIFT S ON SUN NIGHT WITH HIGH NEAR 27N92W WITH A RIDGE SE TO 25N85W THROUGH LATE MON. LIGHT-GENTLE ANTICYCLONIC WINDS EXPECTED GENERALLY N OF 26N TO THE E OF 94W THROUGH FRI NIGHT...WITH MODERATE E-SE WINDS EXPECTED FURTHER OUTWARD AROUND THE S AND SW PERIPHERY OF THE RIDGE. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS OFFICIAL WHICH WAS A GFS/ECMWF BLEND. TAFB NWPS BLENDED WITH PREVIOUS OFFICIAL FOR SEAS HEIGHTS AND PRIMARY WAVE PERIOD. MEDIUM-HIGH CONFIDENCE. ATLC RIDGE N OF THE AREA COMBINED WITH LOW PRESSURE OVER NW COLOMBIA WILL CONTINUE TO MAINTAIN A TIGHT PRESSURE GRADIENT ACROSS THE S-CENTRAL CARIBBEAN THROUGH FRI NIGHT...THEN GUIDANCE SUGGESTS THAT THE ATLC RIDGE WILL SHIFT SOUTHWARD WITH THE ASSOCIATED GRADIENT RELAXING SOME. NOCTURNAL PULSES TO 30 KT ARE EXPECTED WITHIN 150 NM OF THE NW COAST OF COLOMBIA THROUGH FRI NIGHT. NOCTURNAL INCREASE OF TRADES TO 20-25 KT ACROSS THE WESTERN GULF OF HONDURAS IS EXPECTED TO CONTINUE THROUGH FRI NIGHT...THEN 15-20 KT CONDITIONS EXPECTED ON SAT NIGHT AND ONLY 10-15 KT ON SUN AND MON NIGHTS. A TROPICAL WAVE WILL MOVE W THROUGH THE GULF OF HONDURAS TONIGHT INTO EARLY THU. A SECOND TROPICAL WAVE IN THE CENTRAL CARIBBEAN WILL PASS THROUGH THE WESTERN CARIBBEAN ON THU AND FRI. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS OFFICIAL WHICH WAS A GFS/ECMWF BLEND. TAFB NWPS BLENDED WITH PREVIOUS OFFICIAL FOR SEAS HEIGHTS AND PRIMARY WAVE PERIOD. MEDIUM-HIGH CONFIDENCE. A SURFACE HIGH IS MEANDERING JUST SW OF BERMUDA WITH A RIDGE EXTENDING SW TO PORT CANAVERAL FL. THE RIDGE WILL SHIFT SE TO ALONG 29N ON FRI NIGHT WITH THE SURFACE HIGH DEVELOPING NEAR 28N78W. THIS WILL ALLOW A COLD FRONT TO DIP INTO THE ATLC WATERS N OF 28N BETWEEN 65-55W. THE FRONT WILL STALL WITH LOW PRES BRIEFLY DEVELOPING NEAR 31N57W ON THU. THE RIDGE WILL GRADUALLY RE-ORIENTATE FROM E TO W ALONG 27N ON SUN WITH SW WINDS INCREASING TO 15-20 KT N OF 29N ON MON. MODERATE E-SE TRADES ARE OBSERVED S OF THE RIDGE...EXCEPT INCREASING TO 20-25 KT ALONG THE N COAST OF HISPANIOLA AND THE APPROACHES TO THE WINDWARD PASSAGE LATE THIS AFTERNOON INTO EARLY EVENING...WITH THIS PATTERN REPEATING AGAIN ON THU. AN UPPER DISTURBANCE NEAR 24.5N74W IS MOVING W WITH ASSOCIATED DIFFLUENCE ENHANCING CONVECTION OVER ITS NE SEMICIRCLE...AND DENOTED IN WEATHER GRIDS. GUIDANCE SUGGESTS THAT THE LOW WILL DRIFT SW TO OVER SE CUBA WHERE IT WILL MEANDER FROM FRI NIGHT THROUGH SUN NIGHT...THEN DRIFT NW ACROSS THE CAY SAL BANK EARLY MON REACHING AND ACROSS THE BAHAMA CHANNEL ON MON 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 NELSON. NATIONAL HURRICANE CENTER.