000 AGXX40 KNHC 030712 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 315 AM EDT SEP 03 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 IS FORECAST TO SLOWLY MIGRATE NORTHWARD INTO S CENTRAL LOUISIANA OVERNIGHT TONIGHT. A BLEND OF THE 00Z UKMET AND ECMWF IS CLOSEST TO THE OFFICIAL FORECAST THROUGH 48 HOURS BEFORE THE FRONTAL BOUNDARY MAKES ITS WAY TOWARD LEE. AFTER 48 HOURS...THE FASTER AND MORE NORTHERLY 00Z GFS IS CLOSEST TO THE OFFICIAL FORECAST. PRIOR TO THIS...THE GFS IS TOO FAR W WITH THE LOW PRES CENTER. ADJUSTMENTS WERE MADE TO THE FORECAST BASED ON THE 00Z UKMET/ECMWF BLEND THROUGH DAY 2 AND THE GFS THEREAFTER TO KEEP CONSISTENCY WITH THE OFFICIAL FORECAST. THE CURRENT FORECAST KEEPS SIGNIFICANT WAVE HEIGHTS AT OR BELOW 12 FT UNDER THE LONG SOUTHERLY FETCH OVER THE MIDDLE GULF LATE MON INTO TUE. THE MWW3...UKMET WAVE...AND ECMWF SHOW MAX WAVE HEIGHTS APPROACHING THE 16-20 FT RANGE HERE AT THAT TIME. WILL HEDGE ON THE LOWER EDGE OF THIS GUIDANCE FOR NOW...BUT THE GOOD AGREEMENT IN THE WAVE MODELS SUGGESTS CONFIDENCE IN INCREASING THE CURRENT FORECAST. CARIBBEAN SEA AND TROPICAL N ATLC S OF 22N W OF 55W... THE 00Z GFS IS FARTHER N THAN THE OTHER MODELS AND THE OFFICIAL FORECAST CARRYING HURRICANE KATIA THROUGH THE TROPICAL N ATLC ZONE BEGINNING TONIGHT. HOWEVER...IT IS CLOSER TO THE INTENSITY OF THE OFFICIAL FORECAST THAN THE OTHER MODELS. THE 00Z ECMWF IS CLOSEST TO THE OFFICIAL TRACK...BUT IS ALSO N OF THE OFFICIAL FORECAST FROM MON EVENING ON. THE 00Z GFS WILL BE USED AS THE BACKGROUND FORECAST THROUGH SUN AND THEN A DEEPER AND MORE SOUTHERLY VERSION OF THE 00Z ECMWF IS CLOSER TO THE OFFICIAL FORECAST. MEANWHILE...CONDITIONS IN THE CARIBBEAN WILL BE CALMER THAN USUAL AS THE SUBTROPICAL HIGH TO THE NE BECOMES DISRUPTED BY KATIA. SW ATLC S OF 31N W OF 55W... THE 0046 UTC ASCAT PASS SHOWS A SMALL AREA OF FRESH SOUTHERLY WINDS N OF 30N BETWEEN 59W AND 65W. BOTH THE 00Z ECMWF AND GFS SHOW THESE WINDS INITIALLY AND ALLOW THEM TO STICK AROUND THROUGH THIS AFTERNOON BEFORE DISSIPATING. AS FOR HURRICANE KATIA...THE 00Z ECMWF REMAINS CLOSER THAN THE 00Z GFS TO THE OFFICIAL FORECAST TRACK FOR KATIA AS IT TRACKS N OF THE TROPICAL N ATLC ZONE MON. BY THE END OF THE PERIOD WED...THE ECMWF IS SIGNIFICANTLY FARTHER N THAN THE OFFICIAL TRACK. BLENDING ITS SOLUTION WITH THE CMC IS CLOSEST TO THE OFFICIAL FORECAST. WARNINGS... GULF OF MEXICO... .GMZ080...TROPICAL STORM WARNING E OF 93W. .GMZ084...TROPICAL STORM WARNING N OF 25N W OF 86W. CARIBBEAN... .NONE. TROPICAL N ATLC... .AMZ087...HURRICANE WARNING N OF 17N E OF 62W. SW N ATLC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER SCHAUER