000 AGXX40 KNHC 201856 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 300 PM WED SEP 20 2006 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. ATLANTIC...HURRICANE HELENE CENTERED ABOUT 600 NM SE OF BERMUDA NEAR 26.0N 56.3W AT 20/1500 UTC MOVING NW AT 10 KT WITH MAXIMUM SUSTAINED WINDS OF 95 KT AND GUSTS TO 115 KT. HELENE IS EXPECTED TO MOVE NNW OVER THE NEXT 24 HOURS AND THEN BEGIN TO RECURVE NE AHEAD OF AN APPROACHING MID-LATITUDE TROUGH THU NIGHT. SWELLS GENERATED BY HELENE WILL CONTINUE TO AFFECT FORECAST WATERS E OF 70W THROUGH LATE THU. AFTER HELENE MOVES OUT A WEAK RIDGE WILL BUILD NORTH OF THE AREA FRI THROUGH SUN. A COLD FRONT EXTENDING FROM 31N77W TO CENTRAL FLORIDA TODAY WILL MOVE TO 31N67W TO S FLORIDA EARLY THU AND BECOME DIFFUSE BY THU NIGHT. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE POSSIBLE ALONG AND UP TO 240 NM NM AHEAD OF THE FRONT THIS EVENING THROUGH THU. A TROPICAL WAVE ALONG 46W WILL MOVE W INTO THE TROPICAL N ATLC FRI MORNING. GULF OF MEXICO...A COLD FRONT EXTENDS ACROSS THE ENTIRE GULF FROM CENTRAL FLORIDA TO JUST S OF BROWNSVILLE TEXAS. THE FRONT HAS BECOME MORE DIFFUSE TODAY AND ISOLATED SHOWERS ARE POSSIBLE ALONG THE FRONTAL BOUNDARY TONIGHT. HIGH PRESSURE WILL BUILD IN ACROSS THE GULF THU THROUGH SAT BEFORE THE NEXT COLD FRONT MOVES OFF THE TEXAS COAST LATE SUN. RETURN FLOW AROUND THE HIGH SHOULD BRING AN INCREASE IN WINDS AND SEA HEIGHTS TO THE WESTERN GULF AHEAD OF THE APPROACHING FRONT FRI NIGHT THROUGH SUN. CARIBBEAN...THE FRONTAL BOUNDARY ACROSS THE GULF HAS LESSENED THE PRESSURE GRADIENT IN THE CARIBBEAN N OF COLUMBIA AND VENEZUELA SO WINDS AND SEAS ARE RELATIVELY BENIGN ACROSS THE ENTIRE REGION AT THE MOMENT. THE DEVELOPING HIGH PRESSURE RIDGE IN THE GULF AFTER THU WILL BRING AN INCREASE TO TRADE WINDS N OF 12N PRIMARILY BETWEEN 70W AND 75W WITH SEAS BUILDING TO 8 FT FRI NIGHT. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER MUNDELL