000 AGXX40 KNHC 291730 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 200 PM EDT SUN JUL 29 2012 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... W EXTENSION OF ATLC RIDGE CONTINUES FROM CENTRAL FLORIDA TO THE NE TX COAST OCCASIONALLY INTERRUPTED BY A PERSISTENT TROUGH DRIFTING W ACROSS THE NE AND N-CENTRAL GULF RESULTING IN A SURFACE HIGH OF ABOUT 1019 MB DEVELOPING INTERMITTENTLY ALONG THE RIDGE AXIS OVER THE CENTRAL WATERS. NE-E WINDS AT 15-20 KT WILL BE DIURNALLY ENHANCED EACH EVENING ALONG THE NW COAST OF THE YUCATAN PENINSULA. SLY RETURN WILL ONLY MAX AT 15 KT W-CENTRAL WITH ALL GUIDANCE IN FAIRLY CLOSE AGREEMENT. ONLY THE SLIGHTEST HINT OF THE NORTHERN EXTENSION OF A TROPICAL WAVE...CURRENTLY IN THE CARIBBEAN ALONG 71W...EXPECTED TO ENTER THE YUCATAN CHANNEL AREA ON FRI...AND LATER PASS THROUGH THE BAY OF CAMPECHE...ON SAT-SUN. BLENDED LATEST GFS WITH PREVIOUS OFFICIAL FORECAST. SW N ATLC S OF 31N W OF 55W AND TROPICAL ATLC W OF 55W... SURFACE HIGH PRES CENTERED NEAR 31N55W RIDGES WSW TO CENTRAL FL AT 27N. EXPECT THE RIDGE AXIS TO SHIFT NW TO ALONG 31N60W TO 29N80W BY LATE MON...THEN SHIFT S AGAIN TO FL AT 27N BY MID WEEK. GLOBAL GUIDANCE ALL AGREE WITH SLY FLOW NW OF THE RIDGE MAXING AT 15 KT THROUGH THE PERIOD. ELY WINDS WILL CONTINUE AT 15 KT S OF THE RIDGE...BUT ENHANCED BRIEFLY TO 20-25 KT...PER PREVIOUS OBS FROM SISTER SHIPS BATFR14 AND BATFR15...FROM 15N-21N EITHER SIDE OF A TROPICAL WAVE CURRENTLY ALONG 56W. THE WAVE MOTION HAS AVERAGED ABOUT 22 KT THE PAST DAY OR SO...WITH EXTRAPOLATION OF THAT MOTION MOVING THE WAVE THROUGH THE TROPICAL ATLC WATERS TONIGHT AND MON...THEN THE NORTHERN EXTENSION OF THE WAVE WILL SLOW A LITTLE AS IT PASSES THROUGH THE ATLC ZONES AMZ125 AND AMZ123...REACHING ALONG 66W LATE MON...72W LATE TUE...76W EARLY WED THEN CONTINUING THROUGH THE FL STRAITS WED-THU. GFS AND ECMWF IN CLOSE AGREEMENT WITH A 20 KT NE-E-SE WIND SHIFT ALONG THE WAVE...BUT TWEAKED UP THE WINDS IN 1ST COUPLE OF PERIODS TO COMPENSATE FOR EARLIER SHIP REPORTS NEAR THE WAVE AXIS. CARIBBEAN SEA... SURFACE WINDS OVER S-CENTRAL CARIBBEAN ALONG THE COLOMBIAN COAST PEAKED YESTERDAY AND NOW MAX AT ONLY 25 KT. BOTH GFS AND ECMWF AGREE ON A CONTINUED WEAKENING TREND ACROSS THE CENTRAL CARIBBEAN THROUGH ABOUT MIDDAY WED...THEN INCREASING AGAIN TO 20 KT IN ASSOCIATION WITH A TROPICAL WAVE. THE WAVE CURRENTLY MOVING THROUGH THE TROPICAL ATLC WATERS SHOULD MOVE INTO THE E CARIBBEAN MON AFTERNOON...THEN BEGIN TO SLOW REACHING ALONG 70W LATE TUE...76W LATE WED...81W LATE THU...86W LATE FRI...AND MOVING W OF AREA EARLY SAT. A LOW PRES IS CURRENTLY EMBEDDED IN ITCZ NEAR 10N30W. CONSENSUS GUIDANCE HANGS ON TO THIS FEATURE WITH THE GFS THE MOST AGGRESSIVE. ADJUSTED THE WINDS AND ASSOCIATED SEAS DOWN TO MAX AT 25 KT NE SEMICIRCLE ON THE EXTENDED GRIDS. LOW CONFIDENCE COORDINATED MEDIUM RANGE 12Z POSITIONS ARE 10.5N43W WED... 10.548.5W THU...11.5N54W FRI...12.5N60W SAT...AND 13N65.5W SUN. NOTE...GRIDDED MARINE FORECAST IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE GULF OF MEXICO... .NONE. CARIBBEAN SEA... .NONE. SW N ATLANTIC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER NELSON