000
AGXX40 KNHC 170744
MIMATS

MARINE WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
445 AM EDT SUN MAY 17 2009

ATLC AND GULF OF MEXICO...
FORECAST DEVELOPS A SURFACE LOW S OF CUBA TUE AND LIFTS IT 
SLOWLY NORTH TOWARD THE FL KEYS THROUGH TUE NIGHT AND THEN TURNS 
THE SYSTEM MORE NW INTO THE GULF OF MEXICO. AS PER COORDINATION 
WITH HPC AND MFL...SLOWED DOWN THE NORTHERLY PROGRESS OF THE 00Z 
GFS. THE FORECAST RELIES ON A 00Z GFS/ECMWF BLEND. CONFIDENCE IN 
THE GFS DECREASES SIGNIFICANTLY TUE ONWARD AS THE 00Z CONTINUES 
TO OVER-AMPLIFY THE VORTICITY ON THE EASTERN SIDE OF THE MID 
LEVEL LOW...DRAGGING THE LOW TRACK EASTWARD.  HOWEVER...THERE IS 
SOME CONCERN THAT THE GFS MAY BE RIGHT FOR THE WRONG REASONS AS 
THE 00Z UKMET HAS TRENDED MORE EASTERLY WITH THE LOW TRACK AFTER 
THE LOW INCORPORATES THE MID LEVEL VORTICITY FROM THE DEEP LAYER 
TROUGH EXPECTED TO PASS NORTH OF THE SYSTEM MON. FOR NOW...WILL 
SLOWLY TREND TOWARD A MORE EASTERLY TRACK INTO THE GULF OF 
MEXICO TUE-THU...WITH THE STRONGEST WINDS IN THE SW N ATLC N OF 
THE BAHAMAS ON THE NORTHERN SIDE OF THE WARM FRONT AND IN THE 
GULF IN THE NW QUADRANT OF THE LOW WED AND EXPANDING TO N 
SEMICIRCLE THU. MODELS AGREE ON MOVING THE LOW NW INTO THE 
CENTRAL GULF BY THE END OF THE PERIOD AS THE RIDGE TO ITS N 
PASSES E FROM THE TN VALLEY WED AND OFF THE MID ATLC COAST THU.

ATLC ELSEWHERE...THE LOW PRES SYSTEM NEAR 33N523W WILL SLOWLY 
WEAKEN THROUGH THE FORECAST PERIOD.  THERE ARE SOME DIFFERENCES 
IN THE MODELS HERE. THE GFS IS DEEPER THAN THE OTHER MODELS AND 
MORE NORTHERLY WITH THE LOW CENTER FROM TUE EVENING ONWARD.  
CONFIDENCE IS SLIGHTLY HIGHER IN THE GFS HERE. THE TROUGH/COLD 
FRONT MOVING THROUGH THE EASTERN U.S. HAS TRENDED DEEPER OVER 
THE LAST SEVERAL DAYS AND THE MODELS MAY STILL BE TOO WEAK WITH 
IT AS IT APPROACHES THIS LOW FROM THE NW. THE GFS ALLOWS FOR 
MORE INFLUENCE FROM THIS FRONT TO JOG THE LOW NORTHWARD. THIS 
SEEMS REASONABLE.

CARIBBEAN...
LOW DEVELOPING S OF CUBA TUE WILL CONTINUE TO DISRUPT TRADE 
WINDS W OF 75W WITH SOUTHERLY FLOW DOMINANT IN THE NW CARIBBEAN 
EXPECTED TUE THROUGH THU. AS THE LOW LIFTS NORTHWARD...SO SHOULD 
HI PRES CURRENTLY NEAR 34N67W. THIS SHOULD WEAKEN TRADE WINDS IN 
THE EASTERN CARIBBEAN AS WELL.

ATLC...
.AMZ080...GALE CONDITIONS EXPECTED WITHIN 90 NM OF WARM FRONT W 
OF 75W LATE TUE THROUGH THU.

CARIBBEAN...
.NONE.

GULF OF MEXICO...
.GMZ084 AND GMZ086...GALE CONDITIONS EXPECTED N OF 25N E OF 
90W...

FORECASTER SCHAUER CLARK. TROPICAL PREDICTION CENTER.