000 AGXX40 KNHC 041815 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 215 PM EDT THU OCT 4 2007 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. ATLANTIC... A BROAD AREA OF LOW PRES IS LOCATED JUST NE OF THE BAHAMAS...BUT SATELLITE IMAGERY INDICATES THAT IT IS MERELY SEVERAL LOW-LEVEL SWIRLS ROTATING AROUND A COMMON CENTER. STRONG NORTHERLY SHEAR OVER THE SYSTEM IS DISPLACING THE CONVECTION ALONG A TROUGH AXIS TO THE SOUTH AND EAST OF THE MAIN CENTER OF CIRCULATION. IT MAY TAKE ANOTHER 48 HRS OR SO BEFORE UPPER LEVEL WINDS LIGHTEN UP A BIT AND TROPICAL CYCLONE DEVELOPMENT BECOMES A GREATER POSSIBILITY. IN THE MEANTIME...HIGH PRES IS BUILDING TO THE N OF THE LOW AND EASTERLY WINDS ARE INCREASING TO 20 KT N OF 27N. MODEL GUIDANCE INDICATES THAT THE LOW WILL MOVE SW ACROSS THE BAHAMAS ON FRI THEN CROSS CUBA ON SAT...YET THE GRADIENT WILL STILL BE STRONG ENOUGH FOR WINDS TO INCREASE TO 20-25 KT FRI THROUGH SUN MAINLY N OF 25N. WITH THIS DEVELOPMENT OF A LONG EASTERLY FETCH...SEA HEIGHTS ARE EXPECTED TO BUILD TO 8-12 FT E OF FLORIDA. WINDS EASE UP ON MON AND TUE WITH THE RIDGE REMAINING JUST N OF THE AREA...AND EASTERLY SWELLS WILL SUBSIDE BELOW 8 FT BY TUE. FOR THE TROPICAL N ATLC WATERS...WINDS WILL BE GENERALLY LIGHT AND OUT OF THE E/SE FOR MUCH OF THE PERIOD. THE ATLC RIDGE AXIS BUILDS W ON SUN THROUGH THE N PART OF THE AREA WITH WINDS BECOMING MORE SOUTHERLY N OF 18N MON AND TUE. SEAS WILL REMAIN PRIMARILY IN THE 3-5 FT RANGE WITH PERHAPS A LITTLE BIT OF NORTHEASTERLY SWELLS BLEEDING INTO THE REGION. CARIBBEAN... SURFACE TROUGH LIES OVER THE W CARIBBEAN FROM NEAR THE CAYMAN ISLANDS SE TO THE COAST OF COLOMBIA. MODEL GUIDANCE HAS BEEN TRENDING TOWARDS SHOWING THE LOW NEAR THE BAHAMAS MOVING SW OVER THE NEXT FEW DAYS...THEN MERGING WITH THE TROUGH ON SAT. ALTHOUGH CONFIDENCE IN THIS SCENARIO REMAINS LOW...IT STILL APPEARS LIKELY THAT THE TROUGH WILL REMAIN OVER THE W CARIBBEAN THROUGH SUN...THEN BEGIN TO MOVE INLAND OVER CENTRAL AMERICA MON AND TUE. WITH THE TROUGH IN PLACE...WINDS WILL REMAIN LIGHT ACROSS THE ENTIRE AREA WITH SEAS AS LOW AS 1-2 FT IN MANY AREAS. HIGHEST SEAS WILL BE 3-5 FT OVER S/CENTRAL CARIBBEAN WHERE WINDS WILL BE E/SE 10-15 KT FEEDING INTO THE TROUGH. GULF OF MEXICO... A WELL-DEFINED AREA OF LOW PRES IS NOW OVER THE NW GULF NEAR 28N91W BUT IS ESSENTIALLY VOID OF DEEP CONVECTION. THE SYSTEM STILL HAS A SLIGHT POSSIBILITY OF BECOMING A TROPICAL CYCLONE...BUT IT SHOULD BE INLAND OVER SE TEXAS BY FRI AFTERNOON SO ITS WINDOW IS CLOSING. A MORNING QUIKSCAT PASS SHOWED MAXIMUM NON-FLAGGED VECTORS IN THE 20-25 KT RANGE AND MOST MODEL GUIDANCE SHOWS A WEAKENING TREND OVER THE NEXT 24 HOURS. GETTING INTO FRI NIGHT...NORTHEASTERLY WINDS WILL INCREASE TO 20 KT OVER THE FAR NE GULF AS THE PRES GRADIENT TIGHTENS OVER THE W ATLC WATERS AND THIS GRADIENT IS EXPECTED TO PERSIST AND SPREAD W THROUGH TUE PRIMARILY N OF 25N. THE LOW NE OF THE BAHAMAS IS EXPECTED TO MOVE SW AND BE IN THE VICINITY OF THE YUCATAN CHANNEL/PENINSULA BY SUN THROUGH TUE...BUT THERE IS GREAT UNCERTAINTY AT THIS TIME OF HOW WELL-ORGANIZED IT WILL BE. NEVERTHELESS...THIS SYSTEM EVEN AS AN OPEN TROUGH WOULD BE ENOUGH TO INCREASE WINDS TO ITS N. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER BERG