000 WTPZ45 KNHC 071453 TCDEP5 TROPICAL STORM OLIVIA DISCUSSION NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL EP152012 800 AM PDT SUN OCT 07 2012 ALTHOUGH OLIVIA HAS LOST ITS BANDING FEATURES DURING THE LAST SEVERAL HOURS...THE CENTRAL DENSE OVERCAST HAS EXPANDED. A RECENT TRMM PASS AND SHORTWAVE INFRARED IMAGES SHOW A DISTINCT MID-LEVEL CENTER...BUT THE LOW-LEVEL CENTER IS DISPLACED ABOUT 30 N MI TO THE SOUTHWEST OF THE MID-LEVEL FEATURE DUE TO SOUTHWESTERLY VERTICAL WIND SHEAR. ALTHOUGH DVORAK T-NUMBERS HAVE DECREASED A LITTLE THIS CYCLE...THE INITIAL WIND SPEED IS HELD AT 50 KT SINCE THE CENTRAL CONVECTION HAS BECOME SLIGHTLY BETTER ORGANIZED RECENTLY. OLIVIA COULD GAIN SOME STRENGTH DURING THE NEXT 24 HOURS AS THE CYCLONE REMAINS IN ABOUT 10 KT OF SOUTHWESTERLY SHEAR AND STAYS OVER WARM WATERS OF ABOUT 28C. BY LATE TOMORROW...HOWEVER... SOUTHWESTERLY SHEAR IS ANTICIPATED TO INCREASE...WHICH COULD LEAD TO THE DECOUPLING OF OLIVIA. THEREFORE...STEADY WEAKENING IS ANTICIPATED TO COMMENCE AROUND THAT TIME. THE NHC INTENSITY FORECAST IS LOWERED A LITTLE FROM THE PREVIOUS ADVISORY...BUT REMAINS ABOVE MOST OF THE GUIDANCE. TROPICAL STORM OLIVIA HAS SLOWED DOWN...AND THE LATEST INITIAL MOTION ESTIMATE IS 305/5. A TURN TO THE NORTHWEST AND THEN NORTH IS EXPECTED DURING THE NEXT DAY OR SO AS A MID-LEVEL RIDGE OVER BAJA CALIFORNIA AND A DEEP-LAYER LOW LOCATED A FEW HUNDRED MILES WEST OF NORTHERN CALIFORNIA SHIFT SOUTHEASTWARD. BY TUESDAY...OLIVIA IS EXPECTED TO GRADUALLY TURN BACK TOWARD THE WEST OR EVEN SOUTHWEST AS THE WEAKENING SYSTEM BECOMES SHALLOW IN NATURE AND IS STEERED BY THE LOW-LEVEL TRADE WIND FLOW. THE NHC TRACK FORECAST IS ADJUSTED A TAD TO THE RIGHT OF THE PREVIOUS ONE IN THE SHORT-TERM...TRENDING TOWARD THE LATEST GFS AND ECMWF MODELS...BUT IS OTHERWISE SIMILAR TO THE PREVIOUS ADVISORY TRACK AFTER THAT. FORECAST POSITIONS AND MAX WINDS INIT 07/1500Z 14.5N 121.0W 50 KT 60 MPH 12H 08/0000Z 15.2N 121.3W 55 KT 65 MPH 24H 08/1200Z 16.1N 121.4W 60 KT 70 MPH 36H 09/0000Z 16.6N 121.7W 55 KT 65 MPH 48H 09/1200Z 16.8N 122.2W 45 KT 50 MPH 72H 10/1200Z 16.4N 123.8W 35 KT 40 MPH 96H 11/1200Z 15.9N 125.8W 30 KT 35 MPH 120H 12/1200Z 15.3N 128.5W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ FORECASTER CANGIALOSI