000 AGXX40 KNHC 161723 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 123 PM EDT SAT MAY 16 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 IF FOG ACROSS THE NW GULF AND THEREFORE INTRODUCED INTO WEATHER GRIDS THIS EVENING. 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. 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 SUN AND MON EVENINGS...OTHERWISE 15-20 KT ENHANCEMENTS EXPECTED EACH EVENING THROUGH THE END OF THE PERIOD. THESE E-SE PULSES WILL PROPAGATE WNW ACROSS THE SW GULF OF MEXICO E OF AN INVERTED TROUGH DURING THE MORNING DAYLIGHT HOURS...WITH THE TROUGH LOSING IDENTITY AND WINDS DIMINISHED TO 15-20 KT BY THE EARLY AFTERNOONS. THE NORTHERN EXTENT OF THIS 15-20 KT ENHANCEMENT WILL REACH NEAR 25N94W EARLY SUN...BUT ONLY REACH NEAR 23N92W LATE SUN NIGHT. A SURFACE HIGH WILL DEVELOP ALONG THE RIDGE OVER THE NE GULF ON MON NIGHT AND THEN MEANDER OVER THE NE 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 NW FROM COLOMBIA TO THE CENTRAL BAHAMAS. THIS PATTERN SETS UP AN AREA OF UPPER DIFFLUENCE OVER THE SW CARIBBEAN WHERE CONSIDERABLE CONVECTION IS OCCASIONALLY FLARING. 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 OF COURSE FAVORS THIS CONVECTION AND DEVELOPS A SURFACE LOW OVER THE SW CARIBBEAN MID-LATE WEEK. USED A LITTLE MODEL BLENDING TO TONE DOWN THE GFS OUTLIER. ATLC RIDGING N OF THE AREA...COMBINED WITH LOW PRES OVER NW COLOMBIA...WILL SUPPORT 20-25 KT NE WINDS WITHIN 240 NM OF THE NW COAST OF COLOMBIA TONIGHT AND AGAIN ON SUN NIGHT...THEN THE AFFECTED AREA SHOULD SHRINK TO WITHIN 120 NM OF THE COLOMBIAN 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 MAY 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 COLD FRONTAL TROUGH EXTENDING FROM 28N55W TO 24N70W WILL CONTINUE SE AND TRANSITION TO A SHEAR AXIS ACROSS THE TROPICAL WATERS N OF THE ANTILLES THROUGH EARLY NEXT WEEK ACCOMPANIED BY SHOWERS. AN E TO W RIDGE N OF THE AREA WILL SHIFT S WITH A SURFACE HIGH REACHING NEAR 31N70W ON SUN NIGHT WITH A RIDGE W TO EXTREME NE FL. THE HIGH CENTER WILL SHIFT SW TO NEAR 28N73W ON MON NIGHT WITH A RIDGE EXTENDING SE TO 25N60W 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. THE HIGH WILL CONTINUE SHIFT SE REACHING NEAR 26N70W ON TUE NIGHT AND NEAR 25N69W ON WED NIGHT. EXPECT A RIDGE FROM 24N55W TO 28N79W LATE THU WITH A WEAK TROUGH OFF THE NE FL COAST. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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.