000 AGXX40 KNHC 190559 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 200 AM TUE SEP 19 2006 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. UPPER LEVELS... SHORTWAVE TROUGH OVER THE ATLANTIC AREA NORTH OF 25N WILL MOVE NORTHEAST OF THE AREA BY WEDNESDAY AFTERNOON. A LONGERWAVE TROUGH IS OVER THE CENTRAL U.S. AND WILL MOVE EAST REACHING THE EAST GULF OF MEXICO AND FLORIDA AND THE WESTERN PART OF THE ATLANTIC AREA EARLY WEDNESDAY. THE TROUGH WILL CONTINUE EAST AND MOVE NORTH OF 30N OVER THE ATLANTIC AREA THURSDAY. STRONG RIDGE WILL BUILD OVER FLORIDA FRIDAY AND SATURDAY. SURFACE... A COLD FRONT ASSOCIATED WITH THE LONGERWAVE TROUGH MENTIONED ABOVE EXTENDS FROM EASTERN LOUISIANA TO SOUTH TEXAS. THE FRONT WILL MOVE EAST REACHING THE SOUTHEAST U.S. COAST AND THE CENTRAL GULF OF MEXICO TONIGHT AND BERMUDA TO THE NORTHERN BAHAMAS MIDDAY THURSDAY. SOME 20 KNOT WINDS WILL BE AHEAD OF THE FRONT IN THE ATLANTIC AREA MOSTLY NORTH OF ABOUT 28N. AS THE UPPER RIDGE BUILDS OVER FLORIDA THE SURFACE RIDGE WILL ALSO BUILD NORTH OF THE ATLANTIC AREA. THE ASSOCIATED PRESSURE FIELD WILL EXTEND WEST OVER THE GULF OF MEXICO. THIS COUPLED WITH LOW PRESSURE OVER THE U.S. GREAT PLAINS WILL PRODUCE SOUTHERLY WINDS OF 20 KT OVER THE WEST GULF BEGINNING THURSDAY AND CONTINUING THROUGH SATURDAY. TRADES IN THE CARIBBEAN WILL ONLY BE NEAR 20 KT IN THE SOUTH CENTRAL PART OF THIS REGION. HURRICANE HELENE WILL IMPACT THE NORTHERN PART OF THE TROPICAL ATLANTIC WITH WINDS AND SEAS. THE SW NORTH ATLANTIC WILL ONLY EXPERIENCE SEAS ASSOCIATED WITH THE SYSTEM AS THE WINDS ARE EXPECTED TO REMAIN EAST OF THE AREA. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER LL