000 AGXX40 KNHC 240521 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 130 AM SUN SEP 24 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 A FAIRLY STRONG RIDGE IS CENTERED NEAR 29N75W WITH VERY DRY UPPER LAYER ON THE W SIDE ACCORDING TO WATER VAPOR IMAGERY. A MID LEVEL TROUGH WAS OVER THE E CENTRAL ATLC ALONG 43W WITH HRCN HELENE EMBEDDED IN IT FURTHER N. AN INVERTED TROUGH IN THE ELY MID LEVEL FLOW WAS NOTED ALONG 45W AND WAS BEING INFLUENCED BY THE TROUGH TO IT'S N. OVER THE CONUS A STRONG UPPER TROUGH WAS MOVING SE OVER THE MIDWEST. ON THE SURFACE TONIGHT THE ATLC RIDGE EXTENDED FROM A 1022 MB CENTER NEAR 34N63W TO N CENTRAL FL AND THE NRN GULF. A COLD FRONT WAS OVER SE TX MOVING SE WITH AN ACTIVE SQUALL LINE OUT AHEAD OF IT. MODERATE SE WINDS WERE NOTED OVER THE WRN GULF AS WELL AS OVER THE CARIB S OF 18N TONIGHT. A WEAK COLD FRONT WAS NOTED OVER THE NE CORNER OF THE AREA FROM 31N44W TO 27N50W. LATER DAY 1 LITTLE CHANGE TO POSITION OR STRENGTH OF THE MID LEVEL FEATURES. THE TROUGH OVER THE E CENTRAL ATLC BEGINS TO LIFT NE. ON THE SURFACE LATER DAY 1 A SURFACE LOW NEAR 18N44W WILL DRIFT NWD AND HAS SOME POTENTIAL OF DEVELOPING INTO A TROPICAL SYSTEM. OTHERWISE THE ATLC RIDGE WEAKENS SLIGHTLY BUT REMAINS IN PLACE. THE COLD FRONT MOVES OFF THE TX COAST WITH WINDS OF 15 KT. REMAINDER OF THE AREA MOSTLY UNCHANGED. THE RELENTLESS WESTERLIES WITH THEIR STRONG TROUGHS WORK ON THE MID LEVEL RIDGE OVER OUR REGION DAY 2. MID LEVEL HEIGHTS FALL OVER THE NRN GULF. THE RIDGE AT MID LEVELS BEGINS TO RE-POSITION ITSELF OVER MID OCEAN AHEAD OF THE STRONG TROUGH OVER THE ERN US. ON THE SURFACE DAY 2 THE LOW IN THE MID ATLC DRIFTS NWD BUTTING UP AGAINST THE ATLC RIDGE THUS WINDS INCREASE OVER THE NRN SEMICIRCLE OF THE LOW TO 25 KT. THE RIDGE AXIS WEAKENS W OF 70W AS MID LEVEL HEIGHTS FALL ALLOWING THE COLD FRONT TO CONTINUE PUSHING SE OVER THE WARM WATERS OF THE GULF. A 1023 MB HIGH FOLLOWS THE FRONT CENTERED OVER SE TX AND NE WINDS TO 20 KT ARE FORECAST BEHIND THE FRONT. CARIB WINDS REMAIN 15 TO 20 KT S OF 18N. OUTLOOK PERIOD... FOR DAY 3 THE EMERGING MID LEVEL RIDGE FINDS A HOME OVER THE CENTRAL ATLC NEAR 32N47W WITH A WEAK AXIS EXTENDING WSW TO 27N70W. THE WESTERLIES CONTINUE TO CARVE OUT AN AREA BETWEEN 70W AND 85W WITH MID LEVEL HEIGHTS HOLDING FIRM OVER THE WRN GULF. ON THE SURFACE DAY 3 WHATS LEFT OF THE ATLC RIDGE IS CENTERED NEAR 33N43W AT 1022 MB STILL TRYING TO HOLD THE TRPL SYSTEM FROM MOVING NWD. THE GRADIENT WEAKENS ACCORDING TO THE GFS MODEL BUT THAT COULD CHANGE IF IT DEVELOPS. THE MODEL PICKS UP ON A NEW TRPL SYSTEM NEAR 10N37W. THE COLD FRONT OVER THE GULF PULLS UP STATIONARY OVER THE CENTRAL GULF WITH WEAK CYCLOGENESIS TAKING PLACE OFF THE S CAR COAST. WINDS W OF 60W N OF 18N REMAIN 10 TO 15 KT DAY 3 WHILE S OF 18N MOSTLY 15 TO 20 KT IN THE CARIB. DAY 4 FINDS THE WESTERLIES TRYING TO MAKE THE POINT THAT AUTUMN IS HERE AS MID LEVEL HEIGHTS CONTINUE TO FALL BETWEEN 70W AND 90W. A SHORTWAVE MOVES OFF THE SE COAST DAY 4 WHICH WILL AID CYCLOGENESIS. THE MID LEVEL ATLC RIDGE REMAINS NEAR 33N47W WITH A CUTOFF LOW JUST W OF THE CANARIES ACTING AS A BLOCK. ON THE SURFACE DAY 4 THE GFS CONTINUES TO SHOW A WEAK CYCLONIC CIRCULATION MOVING N ALONG 56W WITH WINDS TO 20 KT OVER IT'S NE SEMI. THE GFS ALSO SHOWS A NEW TRPL SYSTEM NEAR 10N40W. A WEAK RIDGE LIES OVER THE GULF WITH LIGHT WINDS DAY 4 AS WEAK LOW PRES REMAINS STATONARY OFF THE S CAR COAST. LITTLE CHANGE TO CARIB WINDS. FOR DAY 5 A NEW SURGE OF COLD AIR ALOFT TAKES PLACE OVER THE NRN PLAINS AND MIDWEST CARVING OUT A LARGE UPPER TROUGH OVER THE ERN US. THUS MID LEVEL HEIGHTS CONTINUE TO FALL W OF 70W ELIMINATING ANY MID LEVEL RIDGE IN THE AREA. THE MID LEVEL RIDGE IS NOW CONFINED TO MID OCEAN NEAR 33N48W BLOCKED BY A CUTOFF LOW NEAR 25N30W. ON THE SURFACE DAY 5 THE GFS CONTINUES TO SHOW SOME SORT OF TRPL LOW MOVING N ALONG 48W BUT IT REMAINS WEAK. NWLY SHEAR ALOFT WILL INCREASE AS THE SYSTEM MOVES CLOSER TO THE STRONG WESTERLIES TO THE N. THE NEXT TRPL SYSTEM SHOWS LITTLE DEVELOPMENT AS IT MOVES TO NEAR 12N42W. WEAK PRESSURE GRADIENT N OF 18N W OF 60W RESULTS IN LIGHT WINDS. CARIB WINDS WEAKEN SOME DAY 5 WITH THE ATLC RIDGE WELL NE. WARNINGS... ATLANTIC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER RRG