ZCZC MIATCDAT3 ALL TTAA00 KNHC DDHHMM TROPICAL DEPRESSION EIGHT DISCUSSION NUMBER 4 NWS NATIONAL HURRICANE CENTER MIAMI FL AL082015 500 PM AST WED SEP 09 2015 The depression's cloud pattern has not become better organized so far today, and the low-level center is exposed a short distance to the west-southwest of the main area of deep convection. The deep convection itself is not well organized, with scant evidence of banding features. Final data T-numbers from TAFB and SAB support keeping the intensity at 30 kt. The vertical wind shear over the system, which is currently near 20 kt from the southwest, is predicted by the global models to relax somewhat over the next 24 to 48 hours. This would allow for some strengthening, as indicated in the official forecast. By 72 hours, the cyclone should be located over cold waters and the global models depict it as embedded within a baroclinic zone. Therefore the system is forecast to be extratropical around that time. The depression is still drifting east-southeastward or 115/3 kt. Over the next couple of days, a mid-level ridge is predicted to build to the east and northeast of the cyclone while a trough drops into the eastern United States. This evolution of the steering pattern should cause the cyclone to move northward at an increasing forward speed into Friday. Afterwards, the flow ahead of the trough should cause the system to turn eastward at an even faster forward speed within the mid-latitude westerlies. The official track forecast is roughly in the middle of the dynamical guidance suite. FORECAST POSITIONS AND MAX WINDS INIT 09/2100Z 30.6N 60.4W 30 KT 35 MPH 12H 10/0600Z 31.9N 60.8W 35 KT 40 MPH 24H 10/1800Z 33.9N 61.0W 40 KT 45 MPH 36H 11/0600Z 36.9N 60.9W 45 KT 50 MPH 48H 11/1800Z 40.7N 59.4W 50 KT 60 MPH 72H 12/1800Z 47.0N 51.0W 45 KT 50 MPH...POST-TROP/EXTRATROP 96H 13/1800Z 48.5N 37.0W 40 KT 45 MPH...POST-TROP/EXTRATROP 120H 14/1800Z 48.0N 18.0W 35 KT 40 MPH...POST-TROP/EXTRATROP $$ Forecaster Pasch NNNN