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Tropical Storm Epsilon Forecast Discussion Number 3
2020-10-19 22:51:41| National Hurricane Center (Atlantic)
Issued at 500 PM AST Mon Oct 19 2020 000 WTNT42 KNHC 192051 TCDAT2 Tropical Storm Epsilon Discussion Number 3 NWS National Hurricane Center Miami FL AL272020 500 PM AST Mon Oct 19 2020 Earlier this afternoon, Epsilon had a hybrid-type structure in satellite imagery, with a partially exposed center and a broken convective band that wrapped around the northern and eastern sides of the storm. However, recent satellite imagery shows a small convective burst near the center that gives Epsilon a more tropical appearance. ASCAT-B/C passes from this morning indicate the system has a large and asymmetric wind field, with 34-kt winds extending over 200 nm away from the center in the northern semicircle. This is, in part, attributable to the environmental pressure gradient with a strong high pressure ridge centered east of the Canadian Maritimes. The initial intensity is raised to 40 kt with this advisory, supported by a T2.5 subjective Dvorak classification from TAFB and a 37-kt objective 14Z SATCON estimate. Warm sea-surface temperatures and moderate southwesterly vertical wind shear should allow for gradual strengthening over the next day or so. By 36-48 h, a period of weaker wind shear should allow Epsilon to continue strengthening while becoming better organized and eventually developing a more symmetric wind field. There is still increasing spread in the intensity guidance beyond 48 h, with a split between the stronger statistical-dynamical guidance and the weaker regional hurricane models. Given these mixed signals, little change was made to the intensity forecast with this advisory. The official NHC intensity forecast lies on the higher end of the guidance consensus, but remains lower than SHIPS/LGEM. The official forecast now calls for Epsilon to become a hurricane on Wednesday. Epsilon remains nearly stationary as it meanders over the central Atlantic under weak steering currents. The cyclone should begin moving slowly northward tonight, then turn northwestward with a faster forward speed through midweek as a mid- to upper-level ridge is expected to build to the north and northeast of Epsilon. The current NHC forecast track shows Epsilon making its closest approach to Bermuda on Friday. By this weekend, the cyclone should begin turning northward ahead of an upper-level trough expected to move off the northeastern U.S. coast. Most of the track guidance is tightly clustered for the next several days, except for the latest HWRF. The track guidance has shifted slightly to the right, and so the NHC track forecast has been adjusted similarly to reflect the latest guidance consensus. Key Message: 1. Epsilon is forecast to be at or near hurricane strength when it approaches Bermuda late this week. While it is too soon to determine the exact details of Epsilon's track and intensity near the island, there is a risk of direct impacts from wind, rainfall, and storm surge on Bermuda, and interests there should closely monitor the progress of Epsilon. FORECAST POSITIONS AND MAX WINDS INIT 19/2100Z 25.5N 55.5W 40 KT 45 MPH 12H 20/0600Z 25.9N 55.5W 45 KT 50 MPH 24H 20/1800Z 27.0N 56.1W 55 KT 65 MPH 36H 21/0600Z 28.1N 57.8W 60 KT 70 MPH 48H 21/1800Z 28.8N 59.4W 65 KT 75 MPH 60H 22/0600Z 29.8N 60.6W 70 KT 80 MPH 72H 22/1800Z 31.1N 61.5W 75 KT 85 MPH 96H 23/1800Z 32.8N 62.8W 80 KT 90 MPH 120H 24/1800Z 35.5N 62.3W 80 KT 90 MPH $$ Forecaster Reinhart/Brown
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