Show Selection: |
#716876 (Received by flhurricane at: 4:54 PM 11.Sep.2014) TCDAT1 TROPICAL DEPRESSION SIX DISCUSSION NUMBER 2 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062014 500 PM AST THU SEP 11 2014 Tropical Depression Six is slowly becoming better organized, with increasing convective banding in the northwestern semicircle. Satellite intensity estimates from TAFB and SAB are 35 kt and 30 kt respectively, and a recent CIRA AMSU estimate was 32 kt. The initial intensity remains 30 kt. The cirrus outflow is good in the northern semicircle and poor elsewhere. The initial motion is 310/13. A low-/mid-level ridge north of the cyclone should steer it generally west-northwestward to northwestward for the next 3-4 days. After that, the track guidance forecasts the system to turn generally northward between the ridge and a large mid-/upper-level low south of Bermuda. the guidance has come into somewhat better agreement that the northward turn should occur between 49W-55W, as the Canadian model has shifted westward since its previous run. The official forecast is an update of the previous package, and it lies near the center of the guidance envelope. The depression remains in an environment of light vertical wind shear. The large-scale models continue to forecast some increase in southerly shear after 24 hours, although less shear is forecast than seen for the previous advisory. The intensity guidance responds to this, and to increasing sea surface temperatures along the forecast track, by showing more intensification than previously, especially after 48 hours. The new intensity forecast is nudged upward from 72-120 hours in best agreement with the intensity consensus. FORECAST POSITIONS AND MAX WINDS INIT 11/2100Z 17.0N 38.2W 30 KT 35 MPH 12H 12/0600Z 17.9N 40.0W 35 KT 40 MPH 24H 12/1800Z 19.0N 42.2W 40 KT 45 MPH 36H 13/0600Z 20.1N 44.3W 45 KT 50 MPH 48H 13/1800Z 21.6N 46.3W 50 KT 60 MPH 72H 14/1800Z 24.5N 50.0W 60 KT 70 MPH 96H 15/1800Z 27.5N 52.5W 65 KT 75 MPH 120H 16/1800Z 30.5N 53.5W 75 KT 85 MPH $$ Forecaster Beven |