ZCZC MIATCDAT2 ALL TTAA00 KNHC DDHHMM TROPICAL DEPRESSION TWELVE DISCUSSION NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122016 1100 PM AST WED SEP 14 2016 The convective pattern of the depression has improved some since the previous advisory with short curved bands having developed in all quadrants. In addition, the upper-level outflow has also improved and become more symmetrical. Satellite intensity estimates range from 30 kt from TAFB and SAB, 37-41 kt in recent AMSU estimates, and an ADT value of T2.8/41 kt. Due to the lack of persistent inner-core convection, the intensity is being maintained at 30 kt. The initial motion is 280/12 kt. A deep-layer ridge to the north of the cyclone is expected steer the system west-northwestward and then westward during the next 48 hours, accompanied by some decrease in forward speed as the ridge weakens slightly. By 72 hours and beyond, the ridge is forecast to build southward slightly, forcing the cyclone on a west-southwestward track over warmer waters. The new forecast track is basically just an update of the previous advisory track, and lies close to the consensus models. Some strengthening is expected during the next 24 hours or so. After that, the cyclone will encounter moderate to strong westerly vertical wind shear caused by a developing upper-level trough to the north of the cyclone. The new intensity forecast continues to show the system weakening back to a depression by 36 hours. On days 4 and 5, some slight re-strengthening is expected when the cyclone moves over SSTs near 28 deg C and into more favorable mid- and upper-level environments as shown by the ECMWF and UKMET models. FORECAST POSITIONS AND MAX WINDS INIT 15/0300Z 17.6N 27.5W 30 KT 35 MPH 12H 15/1200Z 17.8N 29.4W 35 KT 40 MPH 24H 16/0000Z 18.0N 31.9W 35 KT 40 MPH 36H 16/1200Z 18.1N 34.3W 30 KT 35 MPH 48H 17/0000Z 17.9N 36.6W 30 KT 35 MPH 72H 18/0000Z 17.5N 40.7W 30 KT 35 MPH 96H 19/0000Z 17.4N 44.6W 35 KT 40 MPH 120H 20/0000Z 17.9N 49.0W 40 KT 45 MPH $$ Forecaster Stewart NNNN