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#640047 (Received by flhurricane at: 10:38 AM 21.Oct.2013) TCDAT3 TROPICAL DEPRESSION THIRTEEN DISCUSSION NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL AL132013 1100 AM EDT MON OCT 21 2013 THE CLOUD PATTERN OF THE LOW PRESSURE AREA WELL EAST-SOUTHEAST OF BERMUDA HAS CONTINUED TO INCREASE IN ORGANIZATION THIS MORNING. SATELLITE IMAGES SHOW A LONG CURVED BAND OVER THE EASTERN SEMICIRCLE OF THE CIRCULATION...WITH A SMALL CLUSTER OF CONVECTION ON THE EAST SIDE OF THE PARTIALLY EXPOSED LOW-LEVEL CENTER. AN ASCAT PASS LAST NIGHT SUGGESTED THAT THE CENTER WAS BECOMING BETTER DEFINED...AND THE INCREASE IN CONVECTIVE ORGANIZATION SUPPORTS INITIATING ADVISORIES ON THIS SYSTEM. A DVORAK INTENSITY ESTIMATE OF T2.0 FROM TAFB IS THE BASIS FOR THE INITIAL INTENSITY OF 30 KT. THE INITIAL MOTION ESTIMATE IS 040/07. THE DEPRESSION IS FORECAST TO BE STEERED NORTHEASTWARD AROUND THE NORTHWEST SIDE OF A MID- LEVEL RIDGE LOCATED NEAR 27N 47W DURING THE NEXT DAY OR SO. AFTER THAT TIME...THE CYCLONE SHOULD BECOME EMBEDDED IN NEARLY ZONAL FLOW ALONG 30N AND TURN EAST-NORTHWARD UNTIL DISSIPATION. THE NHC TRACK FORECAST IS NEAR BUT JUST AHEAD OF THE MULTI-MODEL CONSENSUS TO ACCOUNT FOR THE FASTER GFS SOLUTION. THE DEPRESSION IS CURRENTLY IN DIFFLUENT FLOW ON THE NORTHEAST SIDE OF AN UPPER-TROPOSPHERIC LOW NORTH OF PUERTO RICO. THE POSITION OF THE TROPICAL CYCLONE RELATIVE TO THIS FEATURE SHOULD KEEP THE WESTERLY SHEAR LOW ENOUGH DURING THE NEXT 24 TO 36 HOURS TO ALLOW FOR SOME INTENSIFICATION WHILE THE DEPRESSION MOVES OVER WARM WATERS. BEYOND 36 HOURS...GLOBAL MODELS SHOW INCREASING WESTERLY SHEAR THAT IS LIKELY TO CAUSE A DECOUPLING OF THE CYCLONE. DISSIPATION IS FORECAST BY 96 HOURS...ALTHOUGH IT COULD OCCUR SOONER. THE NHC INTENSITY FORECAST IS NEAR THE SHIPS/LGEM OUTPUT THROUGH 36 HOURS AND THE NEAR THE MULTI-MODEL CONSENSUS FOR THE REMAINDER OF THE FORECAST PERIOD. FORECAST POSITIONS AND MAX WINDS INIT 21/1500Z 28.0N 55.1W 30 KT 35 MPH 12H 22/0000Z 28.9N 54.1W 35 KT 40 MPH 24H 22/1200Z 29.6N 52.5W 40 KT 45 MPH 36H 23/0000Z 30.1N 50.5W 40 KT 45 MPH 48H 23/1200Z 30.4N 48.9W 35 KT 40 MPH 72H 24/1200Z 31.4N 46.5W 30 KT 35 MPH 96H 25/1200Z...DISSIPATED $$ FORECASTER KIMBERLAIN |