000 AGXX40 KNHC 071842 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 242 PM 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. FOR WAVEHEIGHTS USED BLEND OF LATEST MWW3 AND TAFB NWPS WITH PREVIOUS OFFICIAL. HIGH CONFIDENCE. A NEARLY STATIONARY MID/UPPER LEVEL CYCLONIC CIRCULATION IS NEAR 27N88W WITH A TROUGH EXTENDING SW TO EASTERN BAY OF CAMPECHE. AT THE SURFACE...A 1012 MB LOW IS AT 28N85W. SCATTERED SHOWERS AND TSTMS ARE DEVELOPING OVER MUCH OF THE EASTERN AND CENTRAL GULF ZONES WITH THE ACTIVITY CONTAINING FREQUENT LIGHTNING STRIKES AND POSSIBLE GUSTY WINDS AS IT ROTATES IN A BROAD CYCLONIC FASHION AROUND THE LOW. A WEAK PRES PATTERN IS PRESENT ACROSS THE AREA. LATEST BUOY OBSERVATIONS ARE REPORTING GENERALLY GENTLE WINDS THROUGHOUT WITH WIND DIRECTION IN CYCLONIC FORM OVER THE EASTERN GULF. SEAS REMAIN RELATIVELY LOW...IN THE 1-2 FT RANGE. THE 1012 MB LOW IS FORECAST TO LIFT N WHILE WEAKENING TO A TROUGH ALONG THE FLORIDA PANHANDLE BY TUE MORNING. ATLC HIGH PRES WILL BEGIN TO BUILD WESTWARD ACROSS THE AREA ALONG 27N BEGINNING ON TUE. THE RIDGE WILL SHIFT NORTHWARD TO ALONG 28N ON FRI WITH A HIGH CENTER DEVELOPING NEAR 28N87W. THE WESTERN PERIPHERY OF ATLC HIGH PRES WILL BUILD BACK TO THE W ACROSS THE AREA BEGINNING TUE AND THROUGH SAT WITH A WEAK HIGH PRES CENTER DEVELOPING OVER THE NE GULF. SEAS WILL REMAIN IN THE 1-2 FT RANGE. 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 WED NIGHT...THEN GUIDANCE SUGGESTS WINDS INCREASING TO 15-20 KT AT NIGHT BEGINNING ON WED. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: LATEST GFS BLENDED INTO PREVIOUS OFFICIAL. FOR WAVEHEIGHTS USED BLEND OF LATEST MWW3 WITH PREVIOUS OFFICIAL. HIGH CONFIDENCE...EXCEPT AVERAGE CONFIDENCE TROPICAL N ATLC LATE THU THROUGH SAT. 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 180 NM OF THE COLOMBIAN COAST EACH NIGHT THROUGH WED NIGHT WITH THESE CONDITIONS CONTINUING INTO THE EARLY MORNING HOURS OF THU RESULTING IN COMBINED SEAS OF ABOUT 8-11 FT ON WED. SEAS SUBSIDE 5-8 FT BY LATE THU AND TO 4-5 FT BY SAT AS THE CULPRIT PRESSURE GRADIENT RELAXES. A TROPICAL WAVE OVER THE CENTRAL CARIBBEAN IS NEAR 75W MOVING W AT 10-15 KT. THIS WAVE WILL MOVE ACROSS THE ACROSS THE REST OF THE CENTRAL CARIBBEAN THIS AFTERNOON...AND THE WESTERN CARIBBEAN TONIGHT THROUGH TUE NIGHT. ANOTHER WAVE NEAR 57W...NICELY CAPTURED BY THE 1306 UTC ASCAT WINDS...WILL MOVE ACROSS THE REST OF TROPICAL N ATLC THIS AFTERNOON...THEN ACROSS THE EASTERN CARIBBEAN TONIGHT AND TUE AND OVER THE CENTRAL CARIBBEAN ON TUE NIGHT AND WED AND THE WESTERN CARIBBEAN THU. ANOTHER TROPICAL WAVE WILL MOVE ACROSS THE TROPICAL N ATLC WATERS WED AND WED NIGHT...AND THE EASTERN CARIBBEAN THU AND FRI. CONDITIONS ASSOCIATED WITH TROPICAL STORM GRACE WILL ARRIVE NEAR 16N55W EARLY ON THU AND REACH THE LEEWARDS ON FRI. PRESENTLY...THE LATEST NHC FORECAST HAS GRACE WEAKENING TO A DEPRESSION AS IT MOVES ACROSS THAT PORTION OF THE TROPICAL N ATLC...HOWEVER LARGE SEAS ARE EXPECTED THROUGH ATLC PASSAGES BEGINNING ON FRI. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: LATEST GFS BLENDED INTO PREVIOUS OFFICIAL. FOR WAVEHEIGHTS USED BLEND OF LATEST MWW3 WITH PREVIOUS INCORPORATED TAFB NWPS. HIGH CONFIDENCE. STILL THE MAIN FEATURE IS THE RIDGE THAT EXTENDS NEAR 23N/24N E OF THE NW BAHAMAS AS DEFINED IN THE 1442 ASCAT PASS WINDS AND IN LOW CLOUD OBSERVED MOTION. A WEAK SURFACE TROUGH EXTENDS FROM NEAR 29N65W SW TO THE NW BAHAMAS THE TROUGH WILL SLOWLY MOVE WESTWARD TOWARDS THE FLORIDA COAST ON TUE AND TUE NIGHT. A SURFACE HIGH AT 24N62W WILL SHIFT NW TO 26N67W ON TUE AND NEAR 28N71W ON WED...THEN SHIFT W TO 28N75W EARLY THU WHERE IT WILL LINGER WHILE GRADUALLY LOSING ITS IDENTITY INTO FRI. HIGH PRES WILL BUILD WESTWARD ALONG 27N THU THROUGH SAT. WINDS WILL REMAIN IN THE RATHER GENTLE RANGE WITH SEAS LITTLE CHANGES TO THE CURRENT OBSERVED SEAS OF 1-3 FT. THE ELY TRADES WILL INCREASE TO 15-20 KT ACROSS THE TROPICS WELL E OF THE LEEWARDS...NEAR 20N56W BEGINNING ON THU NIGHT IN ADVANCE TROPICAL CYCLONE GRACE. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 AGUIRRE. NATIONAL HURRICANE CENTER.