000 AGXX40 KNHC 270804 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 304 AM EST SUN JAN 27 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... A 1025 MB HIGH PRES PERSISTS ACROSS THE NE GULF...WITH WEAK FRONTAL BOUNDARY BLOCKED BY HIGH AND NOW STATIONARY ALONG ABOUT 30N ACROSS NE GULF COASTAL WATERS INTO SW N ATLC. RETURN FLOW ACROSS NW GULF HAS BACKED SLIGHTLY PAST 12 HOURS AND IS NOW SE 15-20 KT WITH SEAS 4-5 FT OFFSHORE S TEXAS WATERS. FRESH FLOW ACROSS SE WATERS AND THROUGH STRAITS OF FLORIDA HAS BACKED TO NE IN RESPONSE TO WEAK LLVL PERTURBATION MOVING W ACROSS W CUBA AND NW CARIB. HIGH STILL EXPECTED TO COLLAPSE ACROSS NE GULF THIS AFTERNOON AND EVENING AND ALLOW 1034 MB HIGH ALONG ERN SEABOARD TO SHIFT SE INTO W ATLC AND DOMINATE...PRODUCING MODERATE TO FRESH E-SE FLOW ACROSS THE BASIN THROUGH TUE NIGHT. MODEL GUIDANCE CONTINUES TO INDICATE THAT SUFFICIENT UPPER RIDGING WILL PREVAIL OVER THE GULF TO INHIBIT THE NEXT FEW FRONTAL BOUNDARIES FROM ENTERING THE GULF AS THEY BECOME ILL DEFINED ACROSS N AND NW FLORIDA. THE NEXT COLD FRONT IS STILL EXPECTED TO ENTER NW GULF AROUND 06Z WED...WITH MODELS COMING CLOSER IN TIMING OF THIS EVENT IN RECENT RUNS...WITH ECMWF STILL SLIGHTLY SLOWER...REACHING ONLY FROM SE LA TO TAMPICO BY 12Z...WHILE GFS AND UKMET FARTHER SE...FROM NEAR MOUTH OF MS TO TUXPAN BY 12Z. HAVE NOT BLENDED ECMWF INTO WIND GRIDS...BUT WITH THIS SLIGHTLY SLOWER TREND CONTINUING...WILL HAVE TO RESPECT IT. STRONG NLY FLOW ADVERTISED BY MODELS BEHIND FRONT ALONG MEXICAN WATERS...WITH 30 KT EXPECTED THERE...AND SLIGHT CHANCE FOR GALES ATTM. WHILE DETERMINISTIC OUTPUT STILL SHOWING 30-35 KT PBL FLOW BEHIND FRONT...GFS ENSEMBLES PROBS NOW SHOWING ONLY 10 PERCENT CHANCE FOR GALES AT 12Z WED AND NOTHING AT 18Z. CARIBBEAN SEA AND TROPICAL N ATLC S OF 22N W OF 55W... MODEST PRES GRADIENT CONTINUES ACROSS THE BASIN THIS MORNING WITH A WEAK 1024 MB HIGH CENTERED ACROSS SW N ATLC NEAR 26N73W...BETWEEN TWO FRONTAL BOUNDARIES. A DISSIPATING STATIONARY BOUNDARY CONTINUES FROM CENTRAL ATLC SW THROUGH FAR SRN BAHAMAS TO E CENTRAL CUBA...WITH OBS AND PARTIAL SCATTEROMETER PASSES SUGGESTING ENE WINDS 20 KT ON BOTH SIDES OF BOUNDARY THROUGH S HALF OF BAHAMAS AND ACROSS E AND CENTRAL CUBA. HOWEVER...FRESH FLOW PAST FEW DAYS IN LEE OF CUBA THERE HAS DIMINISHED DUE TO PERTURBATION MENTIONED ABOVE ACROSS W CUBA. WIND AND SEAS HAVE DIMINISHED PAST 12-24 HOURS ACROSS CENTRAL AND W CARIB WITH SEAS DOWN SEVERAL FEET W PORTIONS. STRONG HIGH PRES WILL BUILD ACROSS THE REGION TONIGHT THROUGH WED AS MENTIONED ABOVE AND ACT TO FRESHEN THE TRADES ACROSS THE WHOLE BASIN AND BRING WINDS 25-30 KT OFF OF COLOMBIA...WITH GFS SUGGESTING CHANCE FOR MINIMAL GALES OFF COLOMBIA AT TIME OF NOCTURNAL MAX MON-TUE-WED NIGHTS. SEAS TO BUILD 7-10 FT ACROSS S AND SW PORTIONS AND 6-8 FT ELSEWHERE S OF 17N E OF 80W. A SIGNIFICANT PULSE OF NNW SWELL HAS BEGUN TO REACH THE ATLC COASTAL WATERS OF THE NE CARIB ISLANDS...AND THROUGH THE PASSAGES DURING THE PAST SEVERAL HOURS...AND WILL RAISE SEAS 7-8 FT IN PASSAGES THROUGH SUN. BUOYS ACROSS THE SW N ATLC NEAR 70W HAVE PEAKED AT 10-11 FT OVERNIGHT...WITH AN AFTERNOON 2210 UTC ALTIMETER PASS SHOWING MAX SEAS TO 12.5 FT NEAR 22.5N64.5W...AND 2-4 FT ABOVE WW3 GUIDANCE. STRONG SURF TO AFFECT THE GREATER ANTILLES AND LEEWARDS TONIGHT THROUGH SUN BEFORE FADING SUN NIGHT MON. HAVE TRIED TO BLEND THE HIGHER ECMWF INTO WAVE HEIGHT GRIDS NEXT 24 HOURS TO ACCOUNT FOR LOW BIAS OF WW3. IN THE TROPICAL N ATLC...SEAS ARE BUILDING TO 8-11 FT IN THE THE NRN PORTION AND OVER MOST OF THE CENTRAL PORTION AS NW SWELL IS MIXING WITH NE TRADE WIND SWELL. NW SWELL WILL SUBSIDE MON AND TUE...BUT YET ANOTHER PULSE OF NW SWELLS WITH SEAS ALSO IN THE 9-10 FT MAY MOVE INTO THE FAR NRN PORTION WED PER LATEST WAVE GUIDANCE. SW N ATLC S OF 31N W OF 55W... AS MENTIONED ABOVE...OLD BOUNDARY LINGERS ACROSS THE SW N ATLC THIS MORNING...BUT HAS BEGUN TO WEAKEN AS TUTT OVERHEAD OF THIS FEATURE IS WEAKENING ATTM AS S/W ALOFT EXITS REGION TO THE NE. FRESH ENE FLOW CONTINUES THROUGH SE BAHAMAS TO CENTRAL CUBA WITH SEAS LIKELY TO 7 FT THERE. NEXT FRONT IS SINKING SLOWLY S ALONG 30N ATTM ACROSS NW PORTIONS AND WILL SWEEP SE ACROSS NW PORTIONS THIS MORNING AND REACH NEAR 27N ALONG 70W TONIGHT THEN SETTLE SE ALONG 23-24N AND SLOWLY DISSIPATE THROUGH WED. STRONG HIGH PRES BEHIND IT ALONG THE E COAST OF U.S. WILL SHIFT SE INTO THE W ATLC SUN NIGHT THROUGH WED TO INDUCE FRESH TRADES S OF 24N. N TO NW SWELL PROPAGATING THROUGH THE AREA WATERS ATTM IS REACH THE GREATER ANTILLES AND NRN LEEWARDS...AND HAS PEAKED OVER WATERS N OF N OF 24N AND WILL PEAK ACROSS THE ISLANDS COASTAL WATERS THIS MORNING...AT LIKELY 7-9 FT E OF MONA PASSAGE. NEXT PULSE OF NW SWELL TO MOVE THROUGH WATERS MAINLY E OF 70W MON-TUE. NOTE...GRIDDED MARINE FORECAST IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE WARNINGS... GULF OF MEXICO... .NONE. CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. SW N ATLC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER STRIPLING