000 AGXX40 KNHC 181855 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 255 PM EDT SUN OCT 18 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: GFS-ECMWF CONSENSUS. DRY AND BENIGN SECONDARY FRONT MOVING S AND NE AND CENTRAL PORTIONS OF THE GULF TODAY AS STRONG HIGH PRES BUILDS ACROSS THE N PART OF BASIN AND IS ALSO BRIDGING ACROSS FRONT TO ENHANCE PRES GRADIENT WINDS ACROSS SW PORTIONS. RIDGING ALSO SPILLING DOWN GULF COASTAL STATES OF MEXICO AND THROUGH TEHUANTEPEC REGION TO MAINTAIN GALES ACROSS VERACRUZ AREA...WHERE ISLA SACRIFICIO IS REPORTING MINIMAL GALES ATTM...AND 1536Z ASCAT PASS SHOWED GALES WITHIN 35 NM OF COAST THERE. ASCAT PASS ALSO SUGGESTS LOW PRES CENTER ALONG COAST NEAR 18.5N93.5W AND IS EMBEDDED IN CENTRAL AMERICA MONSOONAL GYRE. STALLED OLD FRONTAL BOUNDARY ALSO LINGERING FROM STRAITS OF FL TO NEAR 21N93.5W. PRES GRADIENT TO THE N OF W END OF THIS BOUNDARY PRODUCING A BROAD ZONE OF NE WINDS AROUND 25 KT...WITH ISOLATED SPOTS TO 30 KT LIKELY...WHERE SEAS ARE 10-12 FT AT LEAST NOW...AND SHIP OBS COMING IN MUCH HIGHER. AS ADVERTISED...MOST OF BASIN NOW LIT UP WITH NE WINDS 20-25 KT AND BUILDING SEAS...RANGING FROM 5-6 FT BIG BEND TO MAX OF 13 OR 14 FT ACROSS SW PORTIONS. GYRE AND OLD FRONTAL BOUNDARY TO COMBINE NEXT 48 HOURS TO PRODUCE CONTINUED ACTIVE WEATHER WITH SCT-NUMEROUS SQUALLS ALONG AND N OF OLD BOUNDARY. GALE TO CONTINUE THROUGH MON EVENING BEFORE WINDS DIMINISH TO 30 KT MON NIGHT THEN GRADUALLY FALLING TO 25 KT THROUGH TUE NIGHT. POTENTIAL LOW DEVELOPING ACROSS BAY OF CAMPECHE AND MOVING NW THROUGH THIS AREA COULD TIGHTEN GRADIENT TUE-WED AND BRING RETURN TO BRIEF GALES COASTAL AREAS. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: GFS. ACTIVE WEATHER CONTINUES ACROSS THE NW CARIBBEAN W OF 83W... BEING SUPPORTED BY ABUNDANT LLVL MOISTURE CONVERGENCE TO THE S OF OLD FRONTAL ZONE IN THE S GULFMEX...THE CENTRAL AMERICAN GYRE...AND RIDGING ALOFT. ALTHOUGH THE GYRE OF FORECAST TO SHIFT SLOWLY W NEXT FEW DAYS...WITH CONTINUE STRONG PRES GRADIENT ACROSS THE GULFMEX AND RIDGING AMPLIFYING ACROSS THE S GULF AND NW CARIB...ACTIVE WEATHER WILL CONTINUE ACROSS COASTAL PORTIONS OF NW CARIB AND YUCATAN CHANNEL THROUGH TUE OR WED. OTHERWISE...LIGHT TO MODERATE TRADES PREVAIL ACROSS ALL BUT NE CARIB DUE TO RELAXED PRES GRADIENT...WITH PEAK TRADES OFFSHORE OF LAGO DE MARACAIBO ONLY 15-20 KT PER 1356Z ASCAT PASS. WEAK E TO SE FLOW ACROSS THE NE CARIB PRODUCING SLIGHT SEAS. LITTLE CHANGE IN PATTERN EXPECTED THROUGH MON BEFORE SINKING FRONT ACROSS SW N ATLC AND ASSOCIATED STRENGTHENING PRES GRADIENT WILL FRESHEN TRADES SLIGHTLY ACROSS S CENTRAL PORTIONS...WITH NOCTURNAL MAX PULSING TO 25 KT OFF OF VENEZUELA AND NE COLOMBIA THROUGH WED MORNING. ALTHOUGH MODELS IN GOOD AGREEMENT THROUGH LATE TUE...THEY BEGIN TO DIVERGE WED-THU ACROSS THE SW N ATLC WITH THE HANDLING OF CYCLOGENESIS ALONG STALLED FRONTAL ZONE THERE...WITH IMPLICATIONS IN WIND FIELD ACROSS ERN CARIB. ENSEMBLE MEANS NOT THAT DIFFERENT THU-FRI AS ELONGATED LOW LIFTS OUT OF REGION. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: GLOBAL MODEL CONSENSUS. OLD FRONTAL BOUNDARY BEING FORCED SE AS DRY AND BENIGN COLD FRONT MOVES SE INTO NW PORTIONS FROM 31N69W TO JUST N OF PALM BEACH ATTM. BOUNDARIES TO GRADUALLY MERGE BY 72 HR AND MEANDER FROM ABOUT 25N65W THROUGH STRAITS AND NW CUBA...WITH AFOREMENTIONED DIFFERING MODERATELY BETWEEN GLOBAL MODELS. BROAD ZONE OF 25 KT NE WINDS WITH AREAS OR NARROW ZONES TO 30 KT TO BUILD ACROSS THE AREA BEHIND SECOND FRONT THIS EVENING THROUGH MON AND GENERATE LARGE AND ROUGH WAVE FIELD SLAMMING INTO FLORIDA AND BAHAMAS COASTS. ASTRONOMICAL TIDES STILL RUNNING HIGH THIS MONTH AND WILL ALLOW FOR BEACH EROSION DURING HIGH TIDES. PEAK SEAS IN THE 12-14 FT RANGE EXPECTED JUST E OF THE BAHAMAS AS FRONT MOVES THROUGH MON AND 8-11 ELSEWHERE BEHIND FRONT. NWPS WITH COUPLED CURRENT OUTPUT YIELDING SEAS 12-13 FT IN THE GULF STREAM FROM CENTRAL FL TO KEYS...AND NOT SURE WHAT TO THINK OF THIS WITH WAVE ACTION NEARLY NORMAL TO GULF STREAM. STRONG ERN U.S. HIGH TO SHIFT E-NE WED AND BEGIN TO ALLOW PRES GRADIENT TO RELAX BEGIN NWD DRIFTING FRONTAL ZONE...BUT AGAIN WITH DIFFERING SOLUTIONS OF LOCATION AND INTENSITY OF CYCLOGENESIS. MUST RESPECT THE ECMWF. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... .GMZ023...SW GULF S OF 22N W OF 94W... GALE WARNING TODAY INTO MON. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 STRIPLING. NATIONAL HURRICANE CENTER.