000 AGXX40 KNHC 180534 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 130 AM WED OCT 18 2006 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. UPPER LEVELS... LARGE MIDDLE AND UPPER ANTICYCLONE CENTERED OVER THE GULF OF MEXICO AND A TROUGH OVER THE ATLANTIC EAST OF 73W. THE ANTICYCLONE WILL ELONGATE TOWARDS THE NORTHEAST WITH A RIDGE FROM BERMUDA TO THE SOUTHWEST GULF ON LATE THURSDAY. THE TROUGH WILL ALSO ELONGATE SOUTH OF THE RIDGE AND BY LATE THURSDAY EXTEND FROM 28N55W TO ACROSS HISPANIOLA TO HONDURAS. BY SATURDAY THE TROUGH WILL BE CONFINED TO THE GREATER ANTILLES AND THE NORTHERN CARIBBEAN AND THE RIDGE WILL WEAKEN AND EXTEND FROM 30N70W TO THE SOUTHWEST GULF OF MEXICO. THE WESTERLIES WILL ALSO EXTEND FURTHER SOUTH TO ABOUT 27N OVER THE GULF OF MEXICO. BY LATE SUNDAY A RIDGE WILL BE ALONG 22N WITH A BREAK IN THE RIDGE OVER CUBA AND THE NORTHWEST CARIBBEAN AND THE WESTERLIES WILL EXTEND TO 26N IN THE GULF OF MEXICO AT THE BASE OF A LONGWAVE MIDDLE LATITUDE TROUGH AND TO NEAR 32N IN THE ATLANTIC AT THE CREST OF THE RIDGE OVER THE ATLANTIC ALONG 22N EAST OF THE GREATER ANTILLES. SURFACE... THE PERSISTENT BROAD LOW CONTINUES OVER THE NORTHEAST AND EAST CARIBBEAN AND IS FORECAST TO LIFT SLIGHTLY NORTH TO OVER THE SOUTHEAST PART OF THE ATLANTIC AREA BY THURSDAY AND MOVE LITTLE THROUGH FRIDAY THEN BEGIN TO MOVE NORTHEAST AND BY SUNDAY TO BE DISSIPATING EAST OF THE ATLANTIC AREA. THE MODEL HAS NOT DONE A PERFECT JOB WITH THIS FEATURE BUT IT HAS FORECAST IT TO BE PERSISTENT AND INDEED IT HAS LASTED MUCH LONGER THAN THE USUAL FEATURE. A COLD FRONT WILL MOVE SOUTH TO THE TEXAS COAST EARLY THURSDAY AND BY FRIDAY EXTEND FROM THE GEORGIA COAST TO THE SOUTHWEST GULF OF MEXICO. THE FRONT WILL WEAKEN AND BY EARLY SATURDAY EXTEND FROM 31N75W TO ACROSS CENTRAL FLORIDA AND BE DIFFUSE IN THE GULF OF MEXICO. EARLY SUNDAY A WEAK PRESSURE PATTERN WILL BE OVER THE AREA WITH THE NEXT COLD FRONT JUST OFF THE TEXAS COAST. BY LATE SUNDAY THE FRONT WILL EXTEND FROM NORTH FLORIDA TO THE NORTHEAST MEXICAN COAST. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER LL