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| #909416 (Received by flhurricane at: 3:45 PM 06.Nov.2017) TCDAT4 Tropical Depression Nineteen Discussion Number 3 NWS National Hurricane Center Miami FL AL192017 500 PM AST Mon Nov 06 2017 The depression has changed little in structure during the past several hours. The low-level center remains exposed to the west of the main area of deep convection due to the influence of westerly shear and dry air. The initial intensity is held at 30 kt based on the earlier ASCAT data and a Dvorak classification of 2.0/30 kt from TAFB. Satellite fixes indicate that the system has been moving slowly and erratically during the past 6 to 12 hours. Smoothing through the wobbles yields an initial motion of 020/5 kt. The combined influences of a mid-level ridge to the east of the depression and a shortwave trough to its west should cause the system to move progressively faster toward the north or north-northeast during the next couple of days. Beyond that time, an even faster northeastward motion is expected when the system becomes embedded in the mid- latitude westerlies. The latest track guidance is notably slower than the previous cycles, and the new NHC track forecast has been adjusted in that direction. The cyclone is expected to remain in an environment of moderate westerly shear while it moves toward cooler waters. Although these conditions typically would not favor strengthening, the models do show the depression deepening during the next couple of days, likely due to some baroclinic forcing and the expected increase in forward speed of the system. The cyclone will likely complete extratropical transition Wednesday night or early Thursday when it merges with a cold front. Overall the intensity guidance has changed little this cycle, and no change was made to the previous NHC intensity prediction. FORECAST POSITIONS AND MAX WINDS INIT 06/2100Z 29.9N 50.0W 30 KT 35 MPH 12H 07/0600Z 31.4N 49.8W 35 KT 40 MPH 24H 07/1800Z 34.2N 49.3W 40 KT 45 MPH 36H 08/0600Z 37.6N 48.4W 45 KT 50 MPH 48H 08/1800Z 41.1N 46.6W 50 KT 60 MPH 72H 09/1800Z 48.8N 37.4W 45 KT 50 MPH...POST-TROP/EXTRATROP 96H 10/1800Z 56.0N 14.0W 35 KT 40 MPH...POST-TROP/EXTRATROP 120H 11/1800Z...DISSIPATED $$ Forecaster Cangialosi |
