000 AGXX40 KNHC 171830 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 230 PM EDT WED SEP 17 2014 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 WITH PREVIOUS/OFFICIAL FORECAST. MWW3 USED FOR WAVE PARAMETERS. HIGH CONFIDENCE. A PRE-FRONTAL TROUGH IS OVER THE NE CORNER OF THE GULF GENERATING SOME SHOWER ACTIVITY. GENTLE NLY WINDS ARE NOTED BEHIND THE TROUGH. A WEAK COLD FRONT WILL FOLLOW THIS TROUGH AND MOVE SLOWLY ACROSS THE CENTRAL AND E GULF THROUGH THU...DISSIPATING BY FRI. ANOTHER TROUGH IS OVER THE SW GULF AND EXTENDS FROM 24N96W TO 19N94W. THERE IS SOME SHOWER ACTIVITY NEAR THE SOUTHERN END OF THE TROUGH. AN ASCAT PASS CONFIRMED THE PRESENCE OF THIS TROUGH FORECAST TO DISSIPATE IN ABOUT 24 HOURS. A 1016 MB HIGH PRES IS IN THE CENTRAL GULF NEAR 26N89W WITH A RIDGE AXIS EXTENDING TO NEAR BROWNSVILLE TEXAS. AN EARLIER ASCAT PASS INDICATED LIGHT TO GENTLE WINDS UNDER THE INFLUENCE OF THE RIDGE WITH SEAS OF 1-3 FT. THE SURFACE HIGH IS FORECAST TO SHIFT INTO THE SE GULF NEAR 24N85W BY THU MORNING AHEAD OF THE COLD FRONT...WHICH WILL GRADUALLY DROP SE-S THROUGH THE GULF E OF 88W. THE FRONT WILL STALL IN THE SE GULF BY FRI MORNING AND WILL DEGENERATE INTO A REMNANT TROUGH WHICH WILL LINGER INTO SAT MORNING. NO OTHER MAJOR IMPACTS ARE EXPECTED WITH THE FRONTAL PASSAGE. EXPECT MODERATE TO LOCALLY FRESH ELY WINDS N OF THE TROUGH AXIS AND MAINLY ACROSS THE N WATERS ON SAT. IN ADDITION... EXPECT MODERATE TO FRESH WINDS NEAR THE COAST OF YUCATAN DURING THE EVENINGS DUE TO LOCAL EFFECTS. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL FORECAST. MWW3 USED FOR WAVE PARAMETERS. HIGH CONFIDENCE. IN THE CARIBBEAN...WEAK RIDGE N OF AREA IS PRODUCING ONLY GENTLE TO MODERATE TRADE WINDS WITH SEAS GENERALLY UNDER 4 FT BASED ON BUOYS AND SOME SHIP OBSERVATIONS. WINDS SLIGHTLY INCREASE ACROSS THE SOUTH-CENTRAL CARIBBEAN WITH SEAS TO AROUND 5 FT. A WEAK PRESSURE PATTERN WILL REMAIN IN PLACE ACROSS THE REGION THROUGH THE REMAINDER OF THE WEEK AND THE UPCOMING WEEKEND WITH WINDS INCREASING ONLY SLIGHTLY TO 15-20 KT IN THE CENTRAL CARIBBEAN WHICH WILL BUILD SEAS TO 4-6 FT. IN THE TROPICAL N ATLC...A TROPICAL WAVE IS CURRENTLY MOVING ACROSS THE REGION AND EXTENDS ALONG 58W S OF 22N. A CLUSTER OF MODERATE CONVECTION IS ASSOCIATED WITH THE WAVE COVERING THE AREA FROM 18N TO 20N BETWEEN 57W AND 59W. THE EDGE OF AN 1300 UTC ASCAT PASS CAPTURED THE WIND SHIFT ASSOCIATED WITH THE WAVE AXIS. THE WAVE WILL MOVE ACROSS THE LESSER ANTILLES TONIGHT...THEN THROUGH THE E CARIBBEAN THU AND THU NIGHT...CENTRAL CARIBBEAN FRI AND FRI NIGHT...THEN WEAKENING AS IT MOVES THROUGH THE W CARIBBEAN. A SECOND TROPICAL WAVE CURRENTLY ALONG 38W S OF 18N WILL CONTINUE TO MOVE WESTWARD REACHING THE TROPICAL N ATLC BY SAT AND THE EASTERN CARIBBEAN ON SUN. SWELLS GENERATED FROM DISTANT HURRICANE EDOUARD WILL BEGIN TO GRADUALLY SUBSIDE ACROSS THE FORECAST REGION LATER TODAY. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS/OFFICIAL FORECAST. MWW3 USED FOR WAVE PARAMETERS. MEDIUM TO HIGH CONFIDENCE. A COLD FRONT IS JUST N OF THE FORECAST REGION WHILE A PRE-FRONTAL TROUGH EXTENDS FROM 31N80W TO ACROSS N FLORIDA INTO THE NE PART OF THE GULF OF MEXICO. THERE IS SOME SHOWER AND TSTM ACTIVITY IN ASSOCIATION WITH THESE FEATURES AFFECTING MAINLY THE WATERS N OF 28N. SIMILAR CONVECTION IS OVER THE SE WATERS. A WEAK RIDGE DOMINATES MAINLY THE EASTERN PART OF THE AREA. LIGHT TO GENTLE WINDS ARE NOTED ACROSS MOST OF THE AREA PER SCATTEROMETER AND SURFACE DATA... BUT WINDS AND SEAS COULD BE HIGHER NEAR THE TSTMS. THE RIDGE WILL SHIFT TO THE E-SE DURING THE NEXT FEW DAYS AS THE PRE-FRONTAL TROUGH AND PARENT COLD FRONT MOVE INTO THE NORTHERN WATERS. THE FRONT IS FORECAST TO EXTEND FROM NEAR 31N73W TO THE NW BAHAMAS THU MORNING...THEN FROM 31N70W TO NEAR SOUTH FLORIDA FRI MORNING WHERE IT WILL STALL...THEN WILL DEGENERATE INTO A TROUGH WHICH WILL RETROGRADE BACK TOWARD THE NW PORTION BY SUN. WEAK LOW PRES IS STILL FORECAST TO FORM ALONG THE FRONT...ALTHOUGH IT STILL APPEARS THAT IT WILL REMAIN ALONG OR JUST N OF 31N. MARINE GUIDANCE SUGGESTS WINDS OF 20-25 KT AHEAD OF THE FRONT AND N OF 28N ON THU...WITH SEAS LIKELY BUILDING TO AROUND 8 FT. EXPECT GENTLE TO MODERATE NLY WINDS BEHIND THE FRONT WITH SEAS 0F 4-5 FT. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 GR. NATIONAL HURRICANE CENTER.