000 AGXX40 KNHC 200504 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 130 AM EDT MON OCT 20 2003 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. THE WESTERLIES CONTINUE TO FLATTEN THE LARGE UPPER RIDGE OVER THE SOUTHERN U.S. TONIGHT. A VIGOROUS UPPER TROUGH IS LIFTING E OFF THE ATLC COAST WITH MOST OF THE ENERGY N OF 30N. WHAT REMAINS S OF 30N IS SLOWLY PUSHING A WEAKENING COLD FRONT OVER THE ATLC WATERS. AT THE SURFACE WEAK CONTINENTAL HIGH BACK OVER THE NW GULF REMAINS ANCHORED UNDER THE UPPER RIDGE. THE HIGH IS FORECAST TO SLOWLY WEAKEN THROUGH DAY 2. WINDS OVER THE ENTIRE AREA ARE IN THE 10 TO 15 KT RANGE. AVN HAS A WEAK LOW ON THE COLOMBIAN COAST AND MOVES IN NW DAY 2. UPPER TROUGHS GIVE WAY DAY 2 TO THE STRONG WESTERLIES WHILE THE SW RIDGE REMAINS IN PLACE. SURFACE FEATURES REMAIN ABOUT THE SAME ALSO. OUTLOOK PERIOD... THE MRF MODEL SHOWS THE AMPLITUDE INCREASING IN THE TROUGH OFF THE E COAST DAY 3 THROUGH 5. MAIN REASON IS A STRONG TROUGH OFF THE W COAST OF THE CONTINENT THAT PUMPS UP THE SW RIDGE. THE RESULT DAY 3 WILL BE CYCLOGENESIS OFF THE E COAST..N OF THE AREA BUT INCREASING WINDS TO 25 KT N OF 28N WITH AN ASSOCIATED COLD FRONT. SURFACE HIGH REMAINS ANCHORED OVER THE SOUTHERN PLAINS AND MAINTAINS A MODERATE NLY FLOW OVER THE GULF. THE LOW IN THE CARIBBEAN IS FORECAST TO TURN NNE AND MOVE TOWARD JAMAICA. DAY 4 FINDS WINDS DECREASING MOST AREAS. THE SURFACE RIDGE OVER THE GULF WEAKENS AND THE COLD FRONT OVER THE ATLC MOVES TO THE SE BAHAMAS. THE CARIBBEAN LOW HEADS NE AND JOINS UP WITH THE COLD FRONT. THE UPPER PATTERN BECOMES MORE PROGRESSIVE DAY 5 WITH THE W COAST TROUGH MOVING INLAND AND FORCING THE UPPER RIDGE OVER THE CENTRAL PLAINS. THIS WILL ALLOW THE SURFACE CONTINENTAL HIGH TO MOVE E OVER THE SE U.S. DAY 5 PRODUCING MODERATE NE WINDS OVER THE ATLC WATERS. THE CARIBBEAN LOW CONTINUES NE ALONG THE OLD FRONT TO NEAR 23N67W DAY 5. CARIBBEAN AND GULF WINDS WILL REMAIN IN THE LIGHT TO MODERATE CATAGORY. WARNINGS... NONE. FORECASTER RRG