000 AGXX40 KNHC 271631 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1230 PM EDT TUE MAR 27 2007 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. UPPER LEVELS... A PERSISTENT TROUGH IS OVER THE ATLANTIC AREA FROM THE EASTERN BAHAMAS EXTENDING NORTHEAST TO 31N60W AND THE SOUTHERN PART OF A MAJOR MIDDLE LATITUDE LONGWAVE TROUGH NORTH OF THE AREA EAST OF 65W. THE PERSISTENT TROUGH WILL REMAIN IN PLACE AND WEAKEN SLIGHTLY THROUGH THURSDAY. A MIDDLE LATITUDE SHORTWAVE WILL DROP SOUTH OVER THE NORTHEAST PART OF THE AREA AND ABSORB THE WEAK TROUGH. THIS SHORTWAVE IS UNUSUAL IN THAT IT WILL CONTINUE TO DROP SLOWLY SOUTH AND BEGIN TO CUT-OFF FROM THE WESTERLY FLOW BEGINNING FRIDAY AND BY SUNDAY BE A WELL DEFINED STRONG CUT-OFF LOW CENTERED NEAR 27N53W. TO THE WEST OF ALL THIS A RIDGE WILL PREVAIL THROUGH SUNDAY EXCEPT FOR THE NORTHWEST PART OF THE GULF OF MEXICO. A MIDDLE LATITUDE SHORTWAVE WILL PASS JUST NORTHWEST OF THE GULF OF MEXICO BEGINNING LATE FRIDAY THEN MOVE A LITTLE NORTH AND BECOME ABSORBED IN THE STRONG WESTERLIES NORTH OF THE AREA SUNDAY. SURFACE... RIDGE ALONG THE NORTHERN BOUNDARY OF THE AREA WILL PERSIST THROUGH WEDNESDAY. A COLD FRONT WILL MOVE SOUTH OVER THE NORTHEAST PART OF THE ATLANTIC AREA WITH HIGH PRESSURE BUILDING NORTH OF THE AREA THROUGH FRIDAY AND CONTINUING THROUGH SUNDAY. A COLD FRONT ASSOCIATED WITH THE SHORTWAVE OVER THE NORTHWEST GULF OF MEXICO WILL MOVE OFF THE TEXAS COAST FRIDAY NIGHT AND REACH THE CENTRAL GULF LATE SATURDAY AND BE A WEAK FRONT OVER THE EAST GULF LATE SUNDAY. ASSOCIATED WITH THE STRONG CUT-OFF LOW A SURFACE LOW WILL DEVELOP LATE FRIDAY NEAR 22N53W AND DRIFT SLIGHTLY NORTH AND INTENSIFY THROUGH SUNDAY. PERIPHERAL NORTHERLY WINDS WILL AFFECT THE EASTERN PART OF THE SW N ATLC REGION AND BY SUNDAY NORTHERLY SWELL GENERATED FROM THE WINDS AROUND THE LOW WILL IMPACT THE TROPICAL ATLANTIC WATERS. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER LL