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#939006 (Received by flhurricane at: 10:56 PM 07.Sep.2018) TCDAT4 Tropical Depression Nine Discussion Number 2 NWS National Hurricane Center Miami FL AL092018 1100 PM AST Fri Sep 07 2018 The depression continues to be impeded by moderate easterly shear with the center of circulation decoupled to the east of a deep convective banding feature. The initial intensity is held at 30 kt based on subjective intensity estimates from TAFB and SAB. The dynamical-statistical intensity guidance, as well as the large-scale models, indicate that the shear should diminish to less than 10 kt within the next 24 hours. A more favorable upper-wind pattern along with warm oceanic temperatures is expected to promote steady strengthening commencing after that time. The intensity forecast is based on a blend of the IVCN and the HCCA consensus models and remains below the stronger HWRF at days 4 and 5. The depression has been meandering during the past several hours, as a result of weak low- to mid-level steering currents created by a deep-layer trough digging southward over the eastern Atlantic. In 12 to 24 hours, a westward motion with a gradual increase in forward speed is forecast thereafter as the trough lifts northeast, and the subtropical ridge re-establishes to the north of the cyclone. The NHC track forecast lies closest to the HCCA and TVCN guidance and takes the system toward the Lesser Antilles by the end of the forecast period. FORECAST POSITIONS AND MAX WINDS INIT 08/0300Z 13.9N 34.9W 30 KT 35 MPH 12H 08/1200Z 14.1N 35.6W 35 KT 40 MPH 24H 09/0000Z 14.2N 36.7W 35 KT 40 MPH 36H 09/1200Z 14.3N 38.4W 45 KT 50 MPH 48H 10/0000Z 14.4N 40.4W 55 KT 65 MPH 72H 11/0000Z 14.4N 45.2W 75 KT 85 MPH 96H 12/0000Z 14.4N 50.2W 80 KT 90 MPH 120H 13/0000Z 14.9N 56.2W 85 KT 100 MPH $$ Forecaster Roberts |