000 AGXX40 KNHC 040704 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 305 AM EDT SEP 04 2011 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... T.S. LEE WILL CONTINUE TO SLOWLY MIGRATE NORTHWARD INTO S CENTRAL LOUISIANA TODAY THEN TURN NE AS A COLD FRONT APPROACHES IT FROM THE NW. THE 00Z GFS IS REASONABLE FOR THE FIRST 24 HOURS OF ITS FORECAST...BUT THEN TRACKS THE SYSTEM FARTHER SE THAN THE OFFICIAL FORECAST THROUGH MS/AL MON BEFORE MOVING BACK TOWARD THE OFFICIAL FORECAST TRACK TUE EVENING. THE 00Z ECMWF IS SIMILAR TO THE GFS. THESE MODELS ARE THE CLOSEST OF THE GLOBAL MODELS TO THE OFFICIAL FORECAST. THE 00Z GFS WILL BE ADJUSTED TOWARD THE OFFICIAL FORECAST THROUGH TUE FOR LEE. THE WW3 SEEMS TO BE DOING A REASONABLE JOB WITH WAVE HEIGHTS WHILE THE ECMWF WAVE MODELS IS 6-8 FT TOO LOW IN THE N CENTRAL GULF COMPARED TO OBSERVATIONS. FINALLY...THE 00Z GLOBAL MODELS GENERALLY AGREE ON GENERATING AN AREA OF LOW PRES IN THE SW GULF BY THU ASSOCIATED WITH THE TAIL END OF THE BAROCLINIC ZONE THAT CAPTURES LEE. CONFIDENCE IS LOW IN THE STRENGTH OF THIS FEATURE. WILL BACKOFF A BIT FROM THE GFS FORECAST WHICH BUILDS A LARGE AREA OF STRONG N WINDS ON THE W SIDE OF THE LOW THU. CARIBBEAN SEA AND TROPICAL N ATLC S OF 22N W OF 55W... THE 00Z GFS IS FASTER THAN THE OFFICIAL FORECAST RIGHT OUT OF THE GATE TODAY WITH KATIA. THE 00Z ECMWF IS CLOSER TO THE OFFICIAL TRACK AS KATIA AS IT LIFTS NW THROUGH THE TROPICAL N ATLC ZONE. MEANWHILE...CONDITIONS IN THE CARIBBEAN WILL BE CALMER THAN USUAL AS THE SUBTROPICAL HIGH TO THE NE BECOMES DISRUPTED BY KATIA. LATE TUE/EARLY WED...THE MODELS GENERALLY AGREE ON CARRYING A TROPICAL WAVE IN THE TROPICAL N ATLC ZONE. THE GFS CARRIES A LARGER AREA OF FRESH WINDS. WITH THE SUBTROPICAL HIGH SLOW TO BUILD IN BEHIND KATIA...WILL SIDE MORE WITH THE 00Z ECMWF WITH THIS FEATURE. SW ATLC S OF 31N W OF 55W... AS KATIA MOVES N OF THE TROPICAL N ATLC ZONE...THE 00Z ECMWF REMAINS THE CLOSEST OF THE GLOBAL MODELS TO THE OFFICIAL TRACK UNTIL WED WHEN ITS PATH SKEWS TO THE SW. THE GFS BECOMES THE BETTER MODEL WED THROUGH FRI WHEN COMPARED TO THE OFFICIAL TRACK. WARNINGS... GULF OF MEXICO... .GMZ080...TROPICAL STORM WARNING N OF 26N E OF 94W. .GMZ084...TROPICAL STORM WARNING N OF 27N W OF 86W. CARIBBEAN... .NONE. TROPICAL N ATLC... .AMZ087...HURRICANE WARNING N OF 18N E OF 62W. SW N ATLC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER