000 AGXX40 KNHC 070519 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 130 AM THU SEP 07 2006 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. LARGE UPPER LEVEL FEATURES DOMINATE THE SCENE TONIGHT ACROSS THE ATLC REGION. A BROAD RIDGE COVERS AN AREA BETWEEN 40W AND 70W FROM 28N NWD. THE RIDGE IS THE DOMINATE FEATURE CONTROLING THE MOTION OF T.S. FLORENCE TONIGHT. A BROAD UPPER TROUGH LIES OVER THE ERN US EXTENDING SW TO THE NW GULF. ON THE SURFACE TONIGHT THE ATLC RIDGE IS CENTERED OVER MID OCEAN WITH IT'S AXIS EXTENDING WSW TO 30N80W. WINDS ACROSS THE REGION ARE MOSTLY LIGHT TO OCCASIONALLY MODERATE E OF 70W. GULF WINDS ARE LIGHT. FOR DAY 1 THE UPPER RIDGE IS EXPECTED TO CHANGE LITTLE WITH IT'S CENTER LOCATED NEAR 34N50W AND BLOCKING FLORENCE FROM TAKING A MORE NLY COURSE. THE UPPER TROUGH OVER THE ERN US WILL MOVE SLOWLY E TO NEAR 90W. ON THE SURFACE THE MAIN CONCERN IS FLORENCE AS SHE MOVES WNW AT 9 KT TO NEAR 21N55W. OTHERWISE LITTLE CHANGE REMAINDER OF THE REGION. DAY 2 FINDS THE UPPER TROUGH OVER THE ERN US WEAKENING AND MOVING ENE. THE UPPER RIDGE HOLDS ON NEAR 34N54W WITH IT'S AXIS EXTENDING SW TO 25N80W. ON THE SURFACE DAY 2 SOME WEAKENING OF THE ATLC RIDGE WITH IT CONTINUING TO BE CENTERED OVER MID OCEAN. A WEAK AXIS WILL EXTEND WSW TO 29N75W WITH FLORENCE EXPECTED TO BECOME A CAT 1 HURRICANE AS IT MOVES TO NEAR 24N61W. MOST AREA WINDS AND SEAS REMAIN LIGHT. OUTLOOK PERIOD... FOR DAY 3 UPPER WINDS WILL REMAIN SWLY OVER THE NRN GULF WITH A NEW SHORTWAVE TROUGH SHOWING UP OVER THE CENTRAL PLAINS. THE ATLC UPPER RIDGE SLIDES EWD TO NEAR 35N52W AND IT'S AXIS WSW ERRODED BY THE SWLY UPPER FLOW. ON THE SURFACE DAY 3 FLORENCE WILL BEGIN TO TAKE ADVANTAGE OF THIS LOSS OF MID LEVEL RIDGE AND BEGIN TO MOVE MORE NWLY TO NEAR 26N65W. A WEAK PRESSURE GRADIENT W OF 70W WILL CONTINUE WITH MOSTLY LIGHT WINDS. DAY 4 ACCORDING TO THE GFS MODEL WILL FIND A MID LEVEL RIDGE BUILDING OVER THE GULF WHILE THE MID ATLC RIDGE SLOWLY MOVES E TO NEAR 35N46W. A WEAKNESS IN THE MID LEVEL PRESSURE FIELD DEVELOPS AND FLORENCE IS EXPECTED TO MOVE INTO IT TO NEAR 29N66W. OUTSIDE OF FLORENCE AND HER AFFECT ON THE ATLC WINDS AND SEAS BETWEEN 55W AND 75W..MOST OTHER AREAS WILL CONTINUE ABOUT THE SAME WITH LIGHT WINDS AND SEAS. FOR DAY 5 THE MID LEVEL RIDGE OVER THE GULF STRENGTHENS WHILE THE MID ATLC RIDGE CONTINUES IT'S EWD TRACK. A WEAKNESS CONTINUES BETWEEN 60W AND 70W WHICH FLORENCE WILL CONTINUE TO EXPLOIT. ON THE SURFACE FLORENCE HEADS NWD DAY 5 TO NEAR 33N66W BUT HER WINDS AND SEAS WILL BE THE DOMINATE FEATURE BETWEEN 55W AND 75W N OF 22N. REMAINDER OF THE REGION WILL REMAIN UNDER A WEAK PRESSURE GRADIENT WITH LIGHT WINDS AND SEAS. WARNINGS... ATLANTIC... HURRICANE CONDITIONS EXPECTED N OF 24N E OF 70W SAT THROUGH MON...AMZ087. TROPICAL STORM WARNING N OF 19N E OF 57W TONIGHT AND THU...AMZ087 WITH HURRICANE CONDITIONS DEVELOPING THU NIGHT AND FRI N OF 20N BETWEEN 56W AND 61W. CARIBBEAN... NONE. GULF OF MEXICO... NONE. FORECASTER RRG