000
AGXX40 KNHC 050716
MIMATS

MARINE WEATHER DISCUSSION       
NWS NATIONAL HURRICANE CENTER MIAMI FL
315 AM EDT SEP 05 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...
WHILE LEE HAS DIMINISHED TO A DEPRESSION...WINDS WILL ONLY 
BRIEFLY DROP BELOW 34 KT OVER GULF WATERS. THE SYSTEM IS BEING 
OVERTAKEN BY A COLD FRONT AND WINDS ARE AGAIN EXPECTED TO 
INCREASE OVER THE NORTHEASTERN GULF WATERS. COORDINATION SUN 
NIGHT WITH COASTAL WEATHER FORECAST OFFICES SIDED ON KEEPING THE 
GALE OUT OF THE OFFSHORE WATERS AND NOTHING IN THE LATEST MODEL 
RUNS SEEMS TO SUGGEST OTHERWISE. THE 00Z MODELS CONTINUE TO 
FAVOR THE DEVELOPMENT OF A LOW PRES SYSTEM ON THE SOUTHERN END 
OF THIS COLD FRONT OVER THE SW GULF TUE/WED. THE 00Z GFS APPEARS 
TO BE A STRONG OUTLIER...SO WINDS IN THE FORECAST PERIOD WILL 
CONTINUE TO SIDE TOWARD THE WEAKER MODEL CONSENSUS AND REMAIN AT 
OR BELOW 20 KT.
  
CARIBBEAN SEA AND TROPICAL N ATLC S OF 22N W OF 55W...
TROPICAL STORM FORCE WINDS ASSOCIATED WITH HURRICANE KATIA 
SHOULD MOVE OUT OF THE TROPICAL N ATLC ZONE THIS MORNING. 
UNCERTAINTY IN THE FORECAST LIES IN THE STRENGTH OF THE TWO 
TROPICAL WAVES OVER THE ATLC...AROUND 43W AND 28W RESPECTIVELY. 
THE 00Z GFS IS STRONGER WITH BOTH OF THESE WAVES THAN THE OTHER 
MODELS... ESPECIALLY THE EASTERN-MOST ONE. THIS WAVE HAS A 
CONSIDERABLY MORE IMPRESSIVE SATELLITE PRESENTATION THAN THE 
WESTERN WAVE. WITH THE SUBTROPICAL RIDGE COMPROMISED BY KATIA 
AND A LINGERING TROUGH N OF 20N ALONG 40W...CONFIDENCE IS LOW IN 
THE LARGE FRESH TO STRONG WIND FIELD GENERATED ON THE N SIDE OF 
THE WESTERN WAVE BY THE GFS. ADJUSTMENTS WILL BE MADE TO THE 
FORECAST TOWARD THE MORE SUBDUED UKMET AND ECMWF FORECASTS HERE 
AS THE WAVE PASSES THROUGH THE TROPICAL N ATLC TUE/WED AND INTO 
THE CARIBBEAN WED EVENING THROUGH FRI. WHILE THE 0Z GFS WEAKENS 
THE EASTERN WAVE AS IT MOVES INTO THE TROPICAL N ATLC 
THU/FRI...IT STILL CARRIES A LARGE AREA OF FRESH TO STRONG WINDS 
WITH IT. THE 00Z ECMWF AND UKMET GENERALLY AGREE...BUT ARE NOT 
QUITE AS STRONG AND SHIFT THE WIND FIELD FARTHER S. BY THIS 
TIME...THE SUBTROPICAL RIDGE SHOULD BE IN PLACE TO THE N. THE 
FORECAST WILL SIDE TOWARD A BLEND OF THE STRONGER GFS AND UKMET 
IN ORDER TO REFLECT THE STRONGER PRES GRADIENT EXPECTED TO BE IN 
PLACE.

SW ATLC S OF 31N W OF 55W...
THE 00Z GFS STRAYS NW OF THE OFFICIAL TRACK FOR HURRICANE KATIA 
BY TUE AS IT MOVES THROUGH THE NE PORTION OF THE ZONE. THE 00Z 
ECMWF STAYS CLOSER TO THE OFFICIAL TRACK THROUGH THE REMAINDER 
OF THE PERIOD AND ITS FORECAST WILL BE USED FOR THE FORECAST 
OUTSIDE OF KATIA FROM TUE EVENING ONWARD. NW WATERS WILL SEE 
FRESH SOUTHERLY FLOW TODAY THROUGH TUE EVENING AHEAD OF THE COLD 
FRONT OVERTAKING THE REMNANTS OF LEE. THE 00Z ECMWF...UKMET AND 
GFS ARE ALL IN AGREEMENT ON THESE CONDITIONS.

WARNINGS...

GULF OF MEXICO...
.NONE.

CARIBBEAN...
.NONE.

TROPICAL N ATLC...
.AMZ087...HURRICANE WARNING N OF 20N FROM 58W TO 63W.

SW N ATLC...
.AMZ080...HURRICANE WARNING E OF 67W FROM 24N TO 30N.
          
FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
FORECASTER SCHAUER