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#906531 (Received by flhurricane at: 4:46 AM 10.Oct.2017) TCDAT2 Tropical Storm Ophelia Discussion Number 5 NWS National Hurricane Center Miami FL AL172017 500 AM AST Tue Oct 10 2017 Although the intensity of Ophelia`s deep convection has decreased during the past several hours, the cloud pattern has improved and become more symmetric with banding features now better established around the center. The initial intensity is held at 45 kt, in agreement with a Dvorak classification from SAB and the latest satellite consensus estimate from CIMSS at the University of Wisconsin. The recent decrease in convection could be associated with some dry air that has wrapped into the circulation, as seen in total precipitable water imagery. The other environmental conditions appear generally conducive for strengthening with wind shear values expected to decrease to near 10 kt during the next couple of days with SSTs remaining marginally warm around 26.5 to 27 deg C. These conditions combined with an unstable atmosphere should allow Ophelia to strengthen, and the NHC forecast follows the IVCN and HCCA consensus models and brings the cyclone to hurricane strength in 24 to 36 hours. Although the official forecast shows slight weakening by the end of the period due to an increase in shear and cooler waters, the latest guidance suggests that the weakening could be less than currently forecast. Satellite fixes indicate that Ophelia has made a turn to the southeast, as expected. A continued slow southeast motion is forecast during the next 36 to 48 hours as mid-level ridging builds to the north and west of the storm. After that time, a turn to the northeast or east-northeast at a progressively faster pace is expected as a mid- to upper-level trough approaches Ophelia. The models are in fairly good agreement, and only minor changes were made to the previous NHC track forecast. This prediction lies near the middle of the guidance envelope. FORECAST POSITIONS AND MAX WINDS INIT 10/0900Z 31.9N 38.8W 45 KT 50 MPH 12H 10/1800Z 31.7N 38.4W 55 KT 65 MPH 24H 11/0600Z 30.8N 37.9W 60 KT 70 MPH 36H 11/1800Z 30.2N 37.4W 70 KT 80 MPH 48H 12/0600Z 30.0N 36.8W 75 KT 85 MPH 72H 13/0600Z 31.0N 35.0W 75 KT 85 MPH 96H 14/0600Z 33.0N 30.5W 75 KT 85 MPH 120H 15/0600Z 35.5N 23.5W 65 KT 75 MPH $$ Forecaster Cangialosi |