000 AGXX40 KNHC 200509 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 130 AM FRI OCT 20 2006 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. IN THE MID LEVELS TONIGHT HEIGHTS ARE FALLING OVER THE SRN US AS A STRONG SHORTWAVE DROPS SE OVER THE MIDWEST. A MID LEVEL RIDGE OVER THE GULF IS FLATTENING OUT AS A RESULT BUT REMAINING STATIONARY. A MID LEVEL RIDGE HOLDS FIRM OFF THE COAST OF AFRICA WHILE A WEAKNESS IN THE PRESSURE FIELD EXISTS BETWEEN 50W AND 70W EXTENDING BACK TO THE NE CARIB. ON THE SURFACE TONIGHT WEAK TROPICAL WAVES WERE ALONG 38W AND 50W MOVING W 10 TO 15 KT. A PERSISTENT WEAK LOW WAS LOCATED JUST N OF PUERTO RICO AND NEARLY STATIONARY. A WEAK COLD FRONT WAS OVER THE NW GULF WITH MOSTLY MODERATE NLY WINDS BEHIND IT. LATER DAY 1 THE MAIN ENERGY IN THE SHORTWAVE WILL SHIFT EWD TOWARD THE NEW ENGLAND AREA AND HAVE NO AFFECT ON OUR REGION. LITTLE CHANGE IN THE OVERALL PATTERN ALOFT S OF 30N. ON THE SURFACE LATER DAY 1 THE GULF COLD FRONT WILL MOVE SLOWLY ESE WITH A WEAK HIGH FOLLOWING IT. THE LOW N OF PUERTO RICO WILL DRIFT WNW WITH SOME WINDS TO 20 KT OVER THE NE QUADRANT. CARIB WINDS MOSTLY LIGHT AS WELL AS ELY TRADES OVER THE ATLC. FOR DAY 2 WHILE THE WESTERLIES REMAIN MOSTLY ZONAL A NEW SURGE OF COLD AIR ALOFT IS POISED TO ENTER THE NRN PLAINS. MID LEVEL PATTERNS S OF 30N BEGIN TO WEAKEN AND SHIFT SLOWLY WWD. ON THE SURFACE DAY 2 THE GULF COLD FRONT STATIONARY OVER N CENTRAL FL WASHES OUT. A VERY WEAK ATLC RIDGE LIES BETWEEN 25N AND 30N BUT ELY TRADES ARE MOSTLY LIGHT. CARIB WINDS ALSO LIGHT. THE WEAK LOW BECOMES A TROUGH OVER THE SE BAHAMAS. OUTLOOK PERIOD... FOR DAY 3 A LARGE MID LEVEL TROUGH BEGINS TO CARVE OUT OVER THE MIDWEST WITH INCREASING PACKING OF HEIGHTS N OF 30N W OF 80W. THE RIDGES S OF 30N WEAKEN FURTHER AS THE WESTERLIES ERODE THEM ALONG 30N. ON THE SURFACE DAY 3 A NEW COLD FRONT ENTERS THE NW GULF WITH WINDS TO 20 KT. REMAINDER OF THE REGION W OF 60W MOSTLY LIGHT WINDS UNDER WEAK PRESSURE GRADIENT. ELY TRADES E OF 60W ALSO LIGHT. FOR DAY 4 MID LEVEL HEIGHTS FALLING ALONG 80W WITH THE MID LEVEL FLOW BECOMING MORE NWLY AS THE BIG UPPER TROUGH SLIDES DOWN OVER THE GREAT LAKES. MID LEVEL RIDGING BEGINS TO REDEVELOP FROM THE CARIB NEWD OVER THE MID ATLC. A WEAKNESS IN THE MID LEVEL PRESSURE FIELD SHIFTS W TO OVER THE WRN CARIB. ON THE SURFACE DAY 4 THE MAIN ACTION WILL BE THE COLD FRONT OVER THE GULF THAT MOVES OFF THE E COAST OF FL BUT HANGES BACK ACROSS S FL INTO THE SRN GULF. A 1024 MB HIGH FOLLOWING THE FRONT WILL MOVE EWD OVER THE DEEP SOUTH PRODUCING NE WINDS 20 TO 25 KT BEHIND THE FRONT. CARIB WINDS BEGINS TO PICK UP JUST A BIT BUT MOSTLY LIGHT TO MODERATE. FINALLY FOR DAY 5 MAIN THRUST OF THE UPPER TROUGH WILL BE EWD OFF THE NE COAST WITH MID LEVEL HEIGHT FALLS SHIFTING E TO ALONG 70W. THIS ALLOWS THE COLD FRONT TO CONTINUE MOVING EWD. SOME MID LEVEL RIDGING BEGINS TO DEVELOP OVER THE WRN GULF WITH A NEW RIDGE BULGING NWD ALONG 40W. ON THE SURFACE DAY 5 THE COLD FRONT RACES EWD TO 65W THEN BACK ACROSS CENTRAL CUBA. THE POLAR HIGH FOLLOWING THE FRONT MOVES SLOWLY OVER THE DEEP SOUTH MAINTAINING GUSTY N AND NE WINDS TO 25 KT N OF 25N BEHIND THE FRONT. REMAINDER OF THE REGION UNDER MOSTLY WEAK PRESSURE GRADIENT AND LIGHT TO OCCASIONAL MODERATE WINDS. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER RRG