000 AGXX40 KNHC 070644 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 244 AM EDT MON SEP 7 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 MID-UPPER LEVEL TROUGH CONTINUES TO DIG S-SW ACROSS THE CENTRAL GULF AND AGAIN ENHANCED CONSIDERABLE CONVECTION YESTERDAY AFTERNOON INTO EARLY EVENING...AND EXPECT THE SAME CONVECTIVE ENHANCEMENT AGAIN THIS AFTERNOON...THUS WILL BE DENOTED IN WEATHER GRIDS FOR TODAY. BROAD LOW PRESSURE DEVELOPED OVER THE NE GULF ON SUN UNDER THE DIFFLUENT AREA E OF THE UPPER TROUGH...BUT IS EXPECTED TO WEAKEN TO AN E TO W ORIENTATED TROUGH ALONG 27N TO THE E OF 89W TODAY. EXPECT THIS WEAK FEATURE TO DRIFT N REACHING THE NORTHERN COASTAL PLAINS TONIGHT AND MOVE INLAND ON TUE 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 28N87W ON FRI. 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 NIGHT. ...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 EACH NIGHT WITH THESE CONDITIONS CONTINUING INTO THE EARLY MORNING HOURS...AND BUILDING COMBINED SEAS TO 7-10 FT. GUIDANCE IS SUGGESTING LITTLE CHANGE THROUGH THU NIGHT...WITH THE AFFECTED AREA SHRINKING TO WITHIN ONLY 60 NM OF THE COAST ON FRI NIGHT. A TROPICAL WAVE WILL PASS THROUGH THE SW CARIBBEAN THIS AFTERNOON THROUGH TUE...AND THROUGH THE GULF OF HONDURAS TUE NIGHT INTO WED. A SECOND TROPICAL WAVE WILL PASS THROUGH THE TROPICAL ATLC WATERS E OF THE WINDWARDS TODAY...PASS THROUGH THE E CARIBBEAN TONIGHT AND TUE...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 TROPICAL STORM GRACE WILL ARRIVE NEAR 16N55W ON THU AND REACH THE LEEWARDS ON FRI. ...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 1017 MB SURFACE HIGH IS AT 24N62W WITH A RIDGE EXTENDING W TO JUST E OF THE NORTHERN BAHAMAS. A LOW LEVEL TROUGH IS ANALYZED N OF THE RIDGE FROM 29N55W TO 28N68W TO THE EXTREME NW BAHAMAS AND IS ACCOMPANIED BY ISOL TS WHICH WILL BE CARRIED IN THE WEATHER GRIDS TODAY INTO TONIGHT. THE TROUGH IS EXPECTED TO DRIFT W AND BECOME ORIENTATED NNE-SSW ALONG THE E FLORIDA COAST N OF 27N ON TUE AND TUE NIGHT. THE SURFACE HIGH WILL SHIFT NW TO NEAR 26N67W EARLY MON...CONTINUE NW TO NEAR 28N71W EARLY WED...THEN SHIFT W TO NEAR 28N75W EARLY THU WHERE IT WILL MEANDER AND GRADUALLY LOSE IDENTITY ON FRI WITH A MORE DOMINATE HIGH DEVELOPING AT 28N55W 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 TROPICAL CYCLONE GRACE WHICH WILL REACH THE VIRGIN ISLAND AREA LATE 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.