000 AGXX40 KNHC 070815 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 315 AM EDT SUN APR 7 2013 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLC...AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... HIGH PRESSURE RIDGE PREVAILS ACROSS THE ERN SEABOARD OF THE U.S. EXTENDING SW INTO THE E CENTRAL GULF...YIELDING MODERATE E TO SE FLOW ACROSS THE ENTIRE BASIN ATTM. WINDS AND SEAS HAVE DIMINISHED CONSIDERABLY IN PAST 24-26 HOURS...WITH MAX SEAS CURRENTLY NEAR 5 FT IN TEXAS COASTAL WATERS. LITTLE CHANGE IN OVERALL CONDITIONS EXPECTED TODAY AS RIDGE REMAINS IN PLACE. WINDS TO VEER SLIGHTLY TONIGHT AND INCREASE ACROSS W HALF AS HIGH SHIFTS SE BETWEEN BERMUDA AND CAPE HATTERAS...AND BEGINS TO OPEN UP INTO DEVELOPING DEEP LAYERED LOW IN THE LEE OF THE ROCKIES. AS THIS LOW BEGINS TO SHIFT E INTO THE CENTRAL PLAINS TUE WINDS ACROSS GULF FORECAST TO INCREASE TO 20-25 KT W HALF AND 15-20 KT MOST OF E HALF. AS LOW CONTINUES TO SHIFT E-NE WED MODELS FORECASTING COLD FRONT TO APPROACH TEXAS COAST WED. DIFFERENCE IN TIMING EXISTS BETWEEN MODELS ATTM WITH GFS FASTER BY AT LEAST 12 HOURS...WHILE ALL GLOBAL MODELS SHOWING N TO S ALIGNED FRONTAL BOUNDARY ALLOWING 20-30 KT OF NLY FLOW TO MOVE OFF TEXAS COAST AND SPILL DOWN MEXICAN COASTAL WATERS AND INTO W BAY OF CAMPECHE BY LATE THU. GEFS MEAN IN LINE WITH TIMING OF GFS ATTM AND WILL BLEND MORE WEIGHT ON GFS FOR UPCOMING PACKAGE. AS RETURN FLOW BECOME WELL ESTABLISHED MON...SEAS BUILD TO 6-7 FT ACROSS NW PORTIONS BUILDING 6-9 FT MOST OF W HALF BY WED. SW N ATLC S OF 31N W OF 55W... COMPLEX LOW PRES AND ASSORTMENT OF FRONTS AND TROUGH S HAS BEEN A DIFFICULT FORECAST PAST FEW DAYS. 00Z SURFACE ANALYSIS REVEALED A PRIMARY 1012 MB ALLOW ALONG 31.5N65W WITH COLD FRONT TRAILING SW TO ERN CUBA WHILE A SECONDARY LOW DEVELOPED UNDERNEATH MIDDLE TO UPPER VORTEX WITHIN UPPER TROUGH...AND TO THE SW OF PRIMARY LOW. 2000 UTC ALTIMETER PASS SHOWED SEAS 8-11 FT ACROSS W SEMICIRCLE OF SECONDARY LOW SUGGESTING AROUND 30 KT OF WIND. GFS HAS HINTED AT GALES DEVELOPING EARLY THIS MORNING IN NW SEMICIRCLE OF PRIMARY LOW AS IT MOVES NE ACROSS BERMUDA...AND AFFECTING WATERS N OF 30N...WHILE EUROPEAN MODELS SHOW THESE GALES DEVELOPING FARTHER NW AND N OF 31N. SHIP WDC6698 HAS BEEN REPORTING NEAR GALE FORCE NLY WINDS IN THIS AREA THE PAST FEW HOURS...BUT THEIR WIND SPEEDS HAVE BEEN DOUBLING AND HALVING PAST 12 HOURS AND CONFIDENCE NOT HIGH. WITH GEFS PROBS KEEPING GALES N OF OUR AREA...31N...AND OPC ISSUING A GALE FOR THIS LOW ALREADY...WILL NOT FORECAST GALES ACROSS OUR WATERS THIS MORNING. LOW TO LIFT OUT TO NE NEXT FEW DAYS AND DRAG WEAKENING FRONT ACROSS SE PORTIONS THROUGH THIS EVENING BEFORE HIGH PRES BEGINS TO RIDGE UNDERNEATH FRONT AND SHIFT REMNANTS NW MON NIGHT THROUGH WED. NE SWELL GENERATED NW OF LOW WILL AFFECT MUCH OF NW AND W PORTIONS THROUGH TUE BEFORE ABATING. STRONG SWLY FLOW AHEAD OF FRONT WILL SHIFT E OF AREA WATERS EARLY THIS MORNING. ACTIVE CONVECTION ALSO SHIFTING E AND NE THIS MORNING AHEAD OF FRONT...WITH MORE ISOLATED TSTMS TO EXTEND SW INTO WATERS OF HISPANIOLA AND PR THROUGH THIS EVENING. BROAD AREA OF FRESH TRADES ACROSS THE TROPICAL ATLC GENERATING TRADE WIND SWELL MOVING INTO TROPICAL ATLC WATERS AND KEEPING SEAS 6-9 FT. WINDS VEERING SE ACROSS N PORTIONS ATTM AND WILL WEAKEN SLIGHTLY NEXT 24 HOURS AS LOW SHIFT N OF AREA AND ASSOCIATED RIDGE AND RESULTANT PRES GRADIENT WEAKENS. WIND AND SEAS TO DIMINISH SLOWLY AND MODESTLY NEXT 48 HOURS. CARIBBEAN SEA AND TROPICAL N ATLC S OF 22N W OF 55W... FRONT ACROSS NW CARIBBEAN HAS BECOME NEARLY STATIONARY...BUT MOVED SE THROUGH THE NICARAGUA COASTAL WATERS TO NEAR THE COSTA RICA BORDER...WITH 0322 UTC ASCAT PASS SHOWING AREA OF 20 KT NLY WINDS BEHIND THE FRONT THERE. LIGHT TO MODERATE WINDS OTHERWISE BEHIND FRONT WITH SEAS 6 FT OR LESS ATTM. FRESH TRADES ACROSS REMAINDER OF CARIB CONFINED TO S OF 14N BETWEEN 63W AND COASTAL COLOMBIA. FRONT WILL BEGIN TO WASH OUT TONIGHT THROUGH MON AND DRIFT NW WHILE HIGH SHIFTS INTO W ATLC AND BEGINS TO FRESHEN TRADEWINDS ACROSS S CENTRAL PORTIONS THROUGH MID WEEK...WITH NOCTURNAL MAX OFF COLOMBIA LIGHTING UP TO 30 KT EACH NIGHT STARTING MON NIGHT...AND GULF OF HONDURAS INCREASING TO 20-25 KT DURING THIS SAME TIME. WARNINGS... GULF OF MEXICO... .NONE. CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. SW N ATLC... .NONE. EFFECTIVE 20 MARCH 2013...TAFB GRIDDED MARINE FORECASTS FOR 10-M WINDS...10-M WIND GUSTS...SIGNIFICANT WAVE HEIGHTS AND HAZARDS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) ON AN EXPERIMENTAL BASIS AT: HTTP://PREVIEW.WEATHER.GOV/GRAPHICAL ADDITIONAL INFORMATION IS AVAILABLE AT WWW.NWS.NOAA.GOV/OM/NOTIFICATION/PNS13OFFSHORE_HIGHSEAS.HTM NOTE...GRIDDED MARINE FORECASTS AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE WILL BE DISCONTINUED ONCE THE "OCEANIC" VIEW IS ADDED TO THE EXPERIMENTAL NDFD GRAPHICAL INTERFACE. $$ FORECASTER STRIPLING