000 AGXX40 KNHC 271748 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 145 PM EDT SAT OCT 27 2007 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... TO THE NORTH OF THE GULF OF MEXICO...SURFACE 1035 MB HIGH PRES CENTERED OVER THE CENTRAL PLAINS IS PUSHING E THROUGH THE MID MISSISSIPPI VALLEY TO THE ERN U.S. BEHIND A AN UPPER TROUGH LIFTING OUT THROUGH THE NEW ENGLAND STATES. MEANWHILE PRESSURE IS LOWERING TO THE SOUTHEAST OF THE GULF...OVER THE CARIBBEAN...AS A DEVELOPING LOW PRES S OF HISPANIOLA IS MOVING SLOWLY INTO THE WESTERN CARIBBEAN. THE PRESSURE GRADIENT BETWEEN THE TWO FEATURES IS TIGHTENING...RESULTING IN INCREASING WINDS AND SEAS FROM THE FLORIDA BIG BEND AREA TO THE WEST CENTRAL GULF. THIS TREND WILL CONTINUE...WITH WINDS AND SEAS INCREASING OVER MOST OF THE GULF OVERNIGHT...ESPECIALLY OVER THE NORTHERN AND WESTERN GULF. GALE CONDITIONS ARE EXPECTED TO START SUNDAY NIGHT OVER THE FAR SW GULF...AND PERSIST THROUGH TUE. WINDS AND SEAS WILL GRADUALLY DIMINISH WED AND THU AS THE HIGH TO THE N WEAKENS AND SHIFTS E AHEAD OF THE FRONT PUSHING THROUGH THEN NORTHERN PLAINS. MEANWHILE...CONVECTION OVER THE SE GULF ASSOCIATED WITH A WEAK STATIONARY FRONT WILL DISSIPATE THROUGH SUN. CARIBBEAN... LOW PRESSURE 1005 MB NEAR 15N71W IS SHOWING A LITTLE BETTER ORGANIZATION THIS MORNING...AND SOME ADDITIONAL DEVELOPMENT IS POSSIBLE. THIS IS THE MAIN FORECAST DRIVER IN THE CARIBBEAN OVER THE NEXT SEVERAL DAYS AND WILL BE WATCHED CLOSELY. WINDS AND SEAS WILL BUILD SLIGHTLY OVER THE EASTERN CARIBBEAN OVERNIGHT BEHIND LOW AS IT MOVES W. WINDS WILL ALSO INCREASE IN THE WATERS BETWEEN JAMAICA AND WESTERN CUBA AS THE LOW MOVES EAST. A TROUGH...ACTUALLY THE SOUTHERN EXTENSION OF A DISSIPATED STATIONARY FRONT...EXTENDS FROM THE YUCATAN CHANNEL TO THE EASTERN TIP OF HONDURAS. MODERATE TO FRESH NWLY WINDS ARE EVIDENT TO THE W OF THIS TROUGH...BUT THIS SHOULD DIMINISH BY TOMORROW. THE LOW WILL MERGE WITH THE TROUGH TO FORM A BROAD AREA OF LOW PRES OVER THE NW CARIBBEAN THROUGH THE MIDDLE OF NEXT WEEK. ATLANTIC... HIGH PRES 1033 MB CENTERED OVER THE NW ATLC WITH SHIFT E IN THE N CENTRAL ATLC THROUGH TOMORROW. SHIP...BUOY AND SCATTEROMETER DATA CONTINUE TO SHOW 20 TO 25 KT WINDS...MAINLY S OF 27N W OF 55W...BETWEEN THE HIGH PRES AND THE LOW OVER THE CARIBBEAN. BUOYS ARE REGISTERING MAINLY 10 FT SEAS...ALTHOUGH SLIGHTLY HIGHER SEAS ARE POSSIBLE IN THE AREA AS LARGE ELY SWELL MOVES THROUGH. E OF 65W...STRONG NELY WINDS AND ASSOCIATED LARGE SWELL PERSIST BETWEEN THE HIGH PRES AND A LOW PRES AREA NEAR 31N45W. THE NEXT HIGH PRESSURE CELL COMING THROUGH THE EASTERN U.S. WILL PLUNGE INTO WESTERN ATLC WATERS ON MONDAY...BEHIND A COLD FRONT THAT WILL EMERGE OFF THE SOUTHEAST U.S. COAST BY SUN NIGHT. THIS ENHANCE ELY FLOW OVER ATLC WATERS W OF 66W. THE MAIN FORECAST ISSUE IS WHETHER OR NOT THERE WILL BE A GALE THROUGH THE BAHAMAS. THE GFS BRINGS THE CARIBBEAN LOW FURTHER N THAN THE OTHER MODELS...AND IS PREDICTING GALE CONDITIONS. THE 00Z ECMWF HAS THE LOW FURTHER S...MORE PLAUSIBLE UNDER CURRENT LOCATION...AND KEEPS THE WINDS TO 20 TO 25 KT. UKMET IS SIMILAR...BUT SHOWS A TIGHTER GRADIENT BETWEEN THE HIGH AND LOW...WITH MOSTLY 30 KT FLOW. WILL EXTEND THE AREA OF 30 KT WINDS IN THE CURRENT FORECAST FURTHER S TO ENCOMPASS THE BAHAMAS. THIS MAY NEED A GALE WARNING FOR TUE IF THE LOW TO THE S DEEPENS DRASTICALLY OR SLOWS. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER CHRISTENSEN