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| #986022 (Received by flhurricane at: 4:32 AM 13.Oct.2019) TCDAT4 Tropical Storm Melissa Discussion Number 8 NWS National Hurricane Center Miami FL AL142019 500 AM AST Sun Oct 13 2019 Satellite images indicate that Melissa has lost organization overnight. Deep convection separated from the low-level center a little before 0000 UTC, and now its convection is confined to a new area about 50 n mi north and northeast of the center. This degraded appearance in the cyclone's structure is due to about 20 kt of westerly vertical wind shear and dry mid-level air. An ASCAT pass from around 0200 UTC showed maximum winds in the 40 to 45 kt range, but since the convective pattern has degraded since then, the initial wind speed is lowered to 40 kt. This estimate is also near an average of the Dvorak FT and CI numbers from TAFB. The westerly shear is expected to increase even more during the next couple of days. These hostile winds aloft combined with the continued influence of dry and stable air should cause continued weakening, and Melissa is forecast to degenerate to a remnant low in about 24 hours, when it is forecast to be over SSTs below 22 C. The global models show the remnants of Melissa becoming absorbed or merging with a front in 2 to 3 days. Melissa has moved a little to the north of the previous track, with the initial motion now estimated to be 065/12 kt. The steering pattern is expected to become more zonal during the next couple of days, which should cause Melissa to move generally eastward at increasing forward speeds before it is absorbed within the frontal zone. The official track forecast is adjusted a little to the north of the previous one to account for the initial motion and position. This forecast lies near the middle of the tightly-packed guidance envelope. FORECAST POSITIONS AND MAX WINDS INIT 13/0900Z 39.3N 62.6W 40 KT 45 MPH 12H 13/1800Z 40.2N 59.9W 35 KT 40 MPH 24H 14/0600Z 41.1N 55.4W 30 KT 35 MPH...POST-TROP/REMNT LOW 36H 14/1800Z 42.0N 50.2W 30 KT 35 MPH...POST-TROP/REMNT LOW 48H 15/0600Z 42.3N 44.5W 30 KT 35 MPH...POST-TROP/REMNT LOW 72H 16/0600Z...DISSIPATED $$ Forecaster Cangialosi |
