000 AGXX40 KNHC 171713 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 113 PM EDT SUN MAY 17 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: FOR WINDS LATEST GFS BLENDED WITH PREVIOUS OFFICIAL. FOR WAVE PARAMETERS TAFB NWPS BLENDED INTO PREVIOUS OFFICIAL. MEDIUM-HIGH CONFIDENCE. LOCAL VISIBILITY AT 3-5 NM IN FOG ACROSS THE NW GULF AND ARE DENOTED IN THE WEATHER GRIDS THIS EVENING. EXPECT THE LOCALIZED EVENING THERMAL ENHANCEMENT ALONG THE NW COAST OF THE YUCATAN PENINSULA TO BE IN THE 20-25 KT RANGE THIS EVENING AND AGAIN ON MON EVENING...OTHERWISE 15-20 KT ENHANCEMENTS EXPECTED EACH EVENING THROUGH THU EVENING. GUIDANCE IS SUGGESTING 20-25 KT CONDITIONS BEGINNING AGAIN ON FRI EVENING. THESE E-SE PULSES WILL PROPAGATE WNW ACROSS THE SW GULF OF MEXICO E OF A WESTWARD MOVING INVERTED TROUGH ALONG 91-92W EACH MORNING AROUND SUNRISE...WITH THE TROUGH LOSING IDENTITY AND WINDS DIMINISHED TO 15-20 KT BY THE EARLY AFTERNOONS. THE NORTHERN EXTENT OF THIS 20-25 ENHANCEMENT WILL REACH NEAR 24N93W EARLY MON...BUT ONLY REACH NEAR 21N92W LATE MON NIGHT. OTHERWISE...A SURFACE RIDGE EXTENDS SW FROM THE FL BIG BEND TO THE NE COAST OF MEXICO. SE-S 15-20 KT CONDITIONS ARE OBSERVED ALONG THE PERIPHERY OF RIDGE WITH 10-15 KT WINDS NOTED ALONG THE RIDGE AXIS OVER THE NE WATERS. A SURFACE HIGH WILL DEVELOP ALONG THE RIDGE OVER THE NE GULF ON MON NIGHT AND THEN MEANDER OVER THE NE AND N-CENTRAL WATERS THROUGH THE END OF THE PERIOD. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: FOR WINDS LATEST GFS/ECMWF BLENDED WITH PREVIOUS OFFICIAL. FOR WAVE PARAMETERS TAFB NWPS BLENDED INTO PREVIOUS OFFICIAL. MEDIUM-HIGH CONFIDENCE. AN UPPER LOW IS CENTERED OVER THE NW CARIBBEAN AND AN UPPER RIDGE EXTENDS N FROM COLOMBIA TO ACROSS HISPANIOLA AND PUERTO RICO. THIS PATTERN CONTINUES TO PROVIDE AN AREA OF UPPER DIFFLUENCE OVER THE SW CARIBBEAN WHERE STRONG CONVECTION OCCASIONALLY FLARES. MOISTURE GUIDANCE SUGGESTS THE SUPPORT WILL CONTINUE FOR SCT SHRA/ISOL TS FOR AT LEAST A COUPLE MORE DAYS ACROSS THE SW CARIBBEAN...AND THIS IS REFLECTED IN THE WEATHER GRIDS. THE GFS IS STILL THE MOST AGGRESSIVE MODEL AND HINTS AT A SURFACE LOW DEVELOPING OVER THE SW CARIBBEAN MID-LATE WEEK WITH A FAIRLY TIGHT GRADIENT DEVELOPING ACROSS THE CENTRAL CARIBBEAN E OF THE LOW. USED MODEL BLENDING TO TONE DOWN THE GFS A TAD. ATLC RIDGING N OF THE AREA...COMBINED WITH LOW PRES OVER NW COLOMBIA...WILL SUPPORT 25-30 KT NE WINDS WITHIN 210 NM OF THE NW COAST OF COLOMBIA TONIGHT...AND 20-25 KT CONDITIONS WITHIN 180 NM OF THE COAST ON MON NIGHT. GUIDANCE WEAKENS THE GRADIENT CONSIDERABLY ON TUE THROUGH THU WITH ONLY A 15-20 KT NOCTURNAL ENHANCEMENT EXPECTED EACH NIGHT. THE GRADIENT IS EXPECTED TO TIGHTEN SLIGHTLY ON THU EVENING WITH 20-25 KT CONDITIONS EXPECTED WITHIN 60 NM OF THE NW COAST OF COLOMBIA. MODERATE TO FRESH TRADE WINDS WILL PREVAIL ACROSS THE REMAINDER OF THE AREA S OF 17N AND MODERATE TRADES N OF 17N. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: FOR WINDS LATEST GFS BLENDED WITH PREVIOUS OFFICIAL. FOR WAVE PARAMETERS TAFB NWPS BLENDED WITH PREVIOUS OFFICIAL WITH MANUAL ADJUSTMENTS TO MATCH OBS AND ALTIMETER DATA. MEDIUM-HIGH CONFIDENCE. A FRONTAL TROUGH EXTENDING FROM 24N55W TO 21N73W WILL CONTINUE SE AND TRANSITION TO A SHEAR AXIS ACROSS THE TROPICAL WATERS N OF THE ANTILLES ON MON AND TUE ACCOMPANIED BY SHOWERS. AN E TO W RIDGE N OF THE AREA WILL SHIFT S WITH A SURFACE HIGH DEVELOPING NEAR 31N70W TONIGHT WITH A RIDGE EXTENDING W TO EXTREME NE FL. THE HIGH CENTER WILL SHIFT WSW TO NEAR 29N74W ON MON EVENING WITH A RIDGE EXTENDING SE TO 27N55W AND A RIDGE EXTENDING NW TO SE GA. THIS RIDGE ORIENTATION WILL ALLOW A COLD FRONT WILL SWEEP SE ACROSS THE WATERS NE OF THE RIDGE AND S OF BERMUDA ON MON NIGHT THROUGH TUE NIGHT. SOUTHERLY FLOW N OF 28N E OF THE FRONT WILL INCREASE TO 20-25 KT...SEAS 7-10 FT...WITH A 15-20 KT SW-W-NW WIND SHIFT...SEAS 5-8 FT...EXPECTED ELSEWHERE ALONG THE FRONT. THESE CONDITIONS WILL PASS E OF 55W ON ON TUE NIGHT. THE HIGH WILL CONTINUE SHIFT SE REACHING NEAR 25N68W ON TUE NIGHT. EXPECT A RIDGE FROM 24N55W TO 25N80W ON WED NIGHT AS A WEAK COLD FRONT DIPS INTO THE FAR NW WATERS AND STALLS FROM 31N75W TO NE FL ON THU. A REINFORCING NW SURGE WILL PUSH THE FRONT E AGAIN ON THU NIGHT INTO FRI WITH THE FRONT STALLING ACROSS THE NORTHERN BAHAMAS ON FRI 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.