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#547610 (Received by flhurricane at: 10:59 PM 03.Oct.2012) TCDAT5 TROPICAL STORM OSCAR DISCUSSION NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL AL152012 1100 PM AST WED OCT 03 2012 THE CLOUD PATTERN OF THE CYCLONE HAS MORPHED INTO A LARGE CLUSTER OF COLD-TOPPED CONVECTION THAT HAS BEEN INCREASING IN INTENSITY AND COVERAGE DURING THE PAST SEVERAL HOURS. HOWEVER...THE LOW-LEVEL CENTER REMAINS EXPOSED ABOUT 60 N MI WEST OF THE NEAREST DEEP CONVECTION AS A CONSEQUENCE OF MODERATE SOUTHWESTERLY SHEAR. AT 0000 UTC...DVORAK T-NUMBERS WERE 2.0 AND 2.5 FROM SAB AND TAFB... RESPECTIVELY...AND A 0030 UTC ASCAT PASS INDICATED SEVERAL UNCONTAMINATED 35 KT WIND BARBS ABOUT 100 N MI EAST OF THE CENTER. BASED PRIMARILY ON THE ASCAT PASS...THE SYSTEM HAS BEEN UPGRADED TO TROPICAL STORM OSCAR WITH A CONSERVATIVE INTENSITY ESTIMATE OF 35 KT. OSCAR IS ON THE CUSP OF ENTERING AN EVEN HIGHER SHEAR ENVIRONMENT IN THE NEXT 12-24 HOURS...WHICH SHOULD PRECLUDE SIGNIFICANT INTENSIFICATION. THE GLOBAL MODELS DEPICT OSCAR OPENING UP INTO A TROUGH AND THEN LOSING ITS IDENTITY AHEAD OF A COLD FRONT IN 36-48 HOURS. THE OFFICIAL FORECAST IS SLIGHTLY HIGHER THAN THE PREVIOUS ONE...BUT STILL SHOWS DISSIPATION IN 48 HOURS. THE FORWARD SPEED OF OSCAR HAS SLOWED SOME IN RECENT HOURS...AND THE INITIAL MOTION ESTIMATE IS NOW 335/10. STEERED BY THE FLOW IN BETWEEN A MID-LEVEL RIDGE NORTH OF THE CAPE VERDE ISLANDS AND A MID-/UPPER-LEVEL TROUGH NORTHEAST OF THE LESSER ANTILLES...OSCAR SHOULD GRADUALLY TURN NORTHWARD DURING THE NEXT 12 HOURS OR SO AS IT DECELERATES FURTHER. AFTER THAT...THE CYCLONE SHOULD BECOME EMBEDDED IN A STRONG AND DEEP-LAYER WESTERLY FLOW SOUTH OF A LARGE MID-/UPPER-LEVEL CYCLONE OVER THE NORTHEAST ATLANTIC...WHICH IS EXPECTED TO RESULT IN A SHARP RECURVATURE AND A NORTHEASTWARD ACCELERATION. ONLY SMALL ADJUSTMENTS WERE MADE TO THE PREVIOUS FORECAST THROUGH 24 HOURS...WITH THE TRACK SHIFTED A BIT TOWARD THE RIGHT PRIOR TO DISSIPATION...WHICH IS IN AGREEMENT WITH THE DYNAMICAL MODEL CONSENSUS. FORECAST POSITIONS AND MAX WINDS INIT 04/0300Z 19.3N 42.2W 35 KT 40 MPH 12H 04/1200Z 20.5N 42.5W 40 KT 45 MPH 24H 05/0000Z 22.0N 41.4W 40 KT 45 MPH 36H 05/1200Z 23.8N 39.4W 40 KT 45 MPH 48H 06/0000Z...DISSIPATED $$ FORECASTER KIMBERLAIN |