000 AGXX40 KNHC 080549 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 149 AM EDT TUE SEP 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 INTO PREVIOUS OFFICIAL WHICH WAS A GFS/ECMWF BLEND. TAFB NWPS USED FOR SEAS HEIGHTS AND PRIMARY WAVE PERIOD WITH MANUAL ADJUSTMENTS TO MATCH OBSERVATIONS. MEDIUM-HIGH CONFIDENCE. A NARROWING MID-UPPER LEVEL TROUGH CONTINUES N TO S ACROSS THE GULF FROM THE MS DELTA TO THE BAY OF CAMPECHE...AND CONTINUES TO ENHANCE CONSIDERABLE LATE AFTERNOON AND EVENING CONVECTION ALONG THE BASE OF THE TROUGH....THUS WILL BE DENOTED IN WEATHER GRIDS FOR FIRST 24 HOURS. UPPER DIFFLUENCE E OF THIS UPPER TROUGH HAS BEEN SUPPORTING THE CONTINUATION OF AN ASSOCIATED WEAK 1011 MB SURFACE LOW OVER THE NE GULF WHICH IN TURN IS ACCOMPANIED BY CONVECTION. EXPECT THE LOW TO WEAKEN TO AN OPEN TROUGH TODAY ORIENTATED NE-SE FROM THE FL BIG BEND TO THE CENTRAL GULF. EXPECT THIS TROUGH TO DRIFT N REACHING THE NORTHERN COASTAL PLAINS TONIGHT...AND MOVE INLAND BY WED NIGHT AS AN ATLC RIDGE BUILDS W ACROSS THE GULF ALONG 27N. THE RIDGE WILL DRIFT N ON WED AND THU WITH A SURFACE HIGH DEVELOPING NEAR 28N84W ON WED NIGHT AND THEN MEANDERING THROUGH EARLY SAT. 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 10-15 KT NOCTURNAL EVENTS THROUGH THU NIGHT...THEN GUIDANCE SUGGESTS A 15-20 KT EVENT ON FRI AND SAT NIGHTS. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: LATEST GFS BLENDED INTO PREVIOUS OFFICIAL WHICH WAS A GFS/ECMWF BLEND. TAFB NWPS USED FOR SEAS HEIGHTS AND PRIMARY WAVE PERIOD WITH MANUAL ADJUSTMENTS TO MATCH OBSERVATIONS. MEDIUM-HIGH CONFIDENCE. THE ATLC RIDGE N OF THE AREA COMBINED WITH LOW PRESSURE OVER NW COLOMBIA WILL CONTINUE TO ENHANCE FRESH TRADES ACROSS THE THE S- CENTRAL WATERS...EXCEPT INCREASING TO STRONG WITHIN ABOUT 210 NM OF THE COLOMBIAN COAST TONIGHT AND ON WED NIGHT...WITH THESE CONDITIONS CONTINUING INTO THE EARLY MORNING HOURS...AND BUILDING COMBINED SEAS TO 7-11 FT. THE GRADIENT IS EXPECTED TO RELAX ON THU AND FRI NIGHTS SUPPORTING ONLY 15-20 KT EVENTS. GUIDANCE IS SUGGESTING AN INCREASE TO 20-25 KT AGAIN ON SAT NIGHT NEAR 13N70W. A TROPICAL WAVE WILL PASS THROUGH THE SW CARIBBEAN TODAY AND THROUGH THE GULF OF HONDURAS TONIGHT INTO WED. A SECOND TROPICAL WAVE WILL ENTER THE SE CARIBBEAN TODAY ACCOMPANIED BY CONSIDERABLE CONVECTION...PASS THROUGH THE CENTRAL CARIBBEAN TUE NIGHT AND WED...REACHING THE W CARIBBEAN LATE THIS WEEK. EXPECT A MODERATE-FRESH NE-E-SE WIND SHIFT NEAR THE WAVES. CONDITIONS ASSOCIATED WITH THE WEAKENING REMNANT LOW OF TROPICAL STORM GRACE WILL ARRIVE NEAR 15N55W LATE WED NIGHT...REACH THE LEEWARDS ON FRI...AND REACH NEAR PUERTO RICO ON FRI NIGHT. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: LATEST GFS BLENDED INTO PREVIOUS OFFICIAL WHICH WAS A GFS/ECMWF BLEND. TAFB NWPS USED FOR SEAS HEIGHTS AND PRIMARY WAVE PERIOD WITH MANUAL ADJUSTMENTS TO MATCH OBSERVATIONS. MEDIUM-HIGH CONFIDENCE. A 1018 MB SURFACE HIGH IS AT 25N59W WITH A RIDGE EXTENDING NW TO 29N74W. A LOW LEVEL TROUGH IS ANALYZED W OF THE RIDGE FROM 28N75W TO 27N80W AND IS ACCOMPANIED BY ISOLATED TS. A SURFACE LOW PRESSURE AT 31N61W HAS STRENGTHENED ALONG A STATIONARY FRONT EXTENDING E TO W ACROSS THE WATERS N OF 29N BETWEEN 55-65W. THE LOW WILL DRIFT E TODAY AND THEN LIFT OUT TO THE N ON WED DRAGGING A WEAK COLD FRONT SE TO A N TO S ORIENTATION FROM 31N63W TO 25N64W ON WED NIGHT. BY THEN THE SURFACE HIGH WILL BE NEAR 29N74W WHERE IT WILL MEANDER AND GRADUALLY LOSE IDENTITY ON FRI WITH A MORE DOMINATE HIGH DEVELOPING AT 28N60W WITH A RIDGE EXTENDING W ACROSS THE ENTIRE AREA ALONG 27N. EXPECT E-SE 10-15 KT FLOW ACROSS THE TROPICAL WATERS S OF THE RIDGE EACH NIGHT THROUGH THU...OTHERWISE 5-10 KT FLOW NEAR THE RIDGE AND LOW AND TROUGH. THE EASTERLY TRADES WILL INCREASE TO 15-20 KT ACROSS THE TROPICS WELL E OF THE LEEWARDS...NEAR 20N56W ON THU NIGHT IN ADVANCE OF REMNANTS OF TROPICAL STORM GRACE WHICH WILL REACH THE VIRGIN ISLAND AREA LATE FRI NIGHT..THESE 15-20 KT CONDITIONS WILL SPREAD N ACROSS THE TROPICS S OF 22N BETWEEN 65W AND 72W ON SAT. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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.