000 AGXX40 KNHC 181911 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 310 PM MON SEP 18 2006 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. SW N ATLC... WEAKENING FRONTAL TROUGH CURRENTLY EXTENDING FROM 31N63W SW TO THE STRAITS OF FLORIDA WILL DISSIPATE OVER E PART LATE TONIGHT INTO TUE MORNING. WEAK HIGH PRES BUILDING SE INTO THE AREA BEHIND THE FRONT WILL CONTINUE TO RESULT IN NW-N 10-15 KT WINDS W OF THE FRONT TO 78W AND SE-S 10 KT WINDS W OF 78W THROUGH TONIGHT. WINDS WILL QUICKLY BECOME SW 15-20 KT OVER THE NW PART TUE AND TUE NIGHT IN ADVANCE OF THE NEXT COLD FRONT EXPECTED TO EMERGE OFF THE U.S. SE COAST TUE NIGHT. THE FRONT WILL REACH A 31N75W TO S FLORIDA LINE WED...THEN BECOME DIFFUSE JUST E OF THE AREA FRI AS HIGH PRES RIDGES S OVER THE W PORTION. MAJOR SWELL EVENT EXPECTED TO BEGIN IMPACTING THE NE PART OF THE AREA LATE WED AND SPREAD WESTWARD TO ABOUT 73W SAT BUT MOSTLY CONFINED TO THE NE PART BY THEN. STILL UNCERTAIN AS TO MUCH SWELL ACTIVITY WILL MAKE IT AROUND THE BAHAMAS TO THEY FLORIDA COAST BY THE END OF THE WEEK. FOR THIS PACKAGE WILL STAY CLOSE TO WORDING OF SEA HEIGHTS AS ADVERTISED IN CURRENT NT3 FOR DAYS 4 AND 5. CARIBBEAN AND TROPICAL N ATLC... WITH ATLC RIDGE HAVING SHIFTED E AHEAD OF THE FRONTAL TROUGH... AND ALSO HURCN HELENE CREATING A BREAK IN THE RIDGE...ELY TRADES FOR THE MOST PART ARE ON THE WEAK SIDE WITH WINDS IN THE SW CARIBBEAN RUNNING ABOUT 15-20 KT FROM 12N-15N BETWEEN 71W-80W. WINDS HERE WILL DECREASE TO 10-15 KT WED THROUGH FRI ALONG WITH SEAS THEN INCREASE 20-25 KT SAT. ELSEWHERE ELY WINDS WILL BE ABOUT 10-15 KT WITH SEAS 3-6 FT EXCEPT 2-3 FT NW PART. OVER THE TROPICAL N ATLC ZONE (AMZ087)...TROPICAL STORM FORCE WINDS AND RESULTANT 12 FT OR GREATER SEAS FROM HURRICANE HELENE ARE NOW EXPECTED TO SKIRT ALONG THE EXTREME NE PART OF THE TROPICAL ATLC AREA TUE THROUGH EARLY WED AFTERNOON THEN SLOWLY SUBSIDE THU AND FRI. EXPECT NE LONG PERIOD SWELLS OF UP 7 FT TO AFFECT THE ATLC PASSAGES OVER THE NE CARIBBEAN SEA LATE WED ...THEN SUBSIDING TO 6 FT FRI AND TO 4 FT BY SAT. GULF OF MEXICO... THE COMBINATION OF LOW PRES OVER W TEXAS AND HIGH PRES EXTENDING SW ALONG THE N GULF COAST WILL CONTINUE TO RESULT IN MODERATE SLY WINDS OVER THE W GULF THROUGH TONIGHT OVER THE W GULF. THIS IS IN ADVANCE OF A RATHER WELL PRONOUNCED COLD FRONT JUST INLAND THE TEXAS COAST THAT WILL MOVE INTO THE W GULF EARLY THIS EVENING. ALL NUMERICAL MODELS EXCEPT FOR THE GFS AND CANADIAN ARE PRETTY GOOD AGREEMENT WITH POSITIONING AND TIMING OF FRONTAL POSITION ACROSS THE GULF THROUGH THE FIRST 12-24 HRS WITH GFS/CANADIAN A BIT TOO FAST. AFTER 24 HRS MODELS THEN ARE IN GOOD AGREEMENT WITH TIMING AND POSITION. EXPECT FLOW BEHIND FRONT TO BE NW-N 15 KT MON NIGHT THEN BECOMING MORE N-NE 15 KT TO OCCASIONALLY 20 KT THROUGH TONIGHT AND WED OVER THE N PORTION OF THE MIDDLE GULF. FRONT WILL EXTEND FROM N FLORIDA SW TO BAY OF CAMPECHE WED...AND EXIT THE GULF THU. NLY WINDS WILL DECEASE QUICKLY THU AND FRI AS FRONT EXITS THE GULF. STRONG SLY FLOW IN THE RANGE OF 15-20 KT INCREASES ONCE AGAIN OVER THE W GULF LATE THU INTO FRI AND CONTINUES THROUGH SAT AS LOW PRES DEEPENS OVER THE MID-WEST AND ATLC HIGH PRES DIGS SW ALONG THE U.S. EASTERN SEABOARD AND THE NE GULF. NEXT COLD FRONT ASSOCIATED WITH THE LOW PRES WILL MOVE INTO THE NW GULF SAT. WINDS AND SEAS WILL BE RATHER LIGHT ACROSS REMAINDER OF GULF. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER AGUIRRE