ZCZC MIATCDAT2 ALL TTAA00 KNHC DDHHMM Tropical Storm Epsilon Discussion Number 5 NWS National Hurricane Center Miami FL AL272020 500 AM AST Tue Oct 20 2020 Epsilon continues to have a non-standard appearance in satellite imagery this morning. While an area of convection is near and over the center, the center is also near the western end of a baroclinic zone, and that is giving the storm the look of a occluded extratropical low. In addition, water vapor and air mass imagery indicate that an upper-level trough is close to the system in the southwestern semicircle. Satellite intensity estimates have not changed significantly since the last advisory, so the initial intensity is unchanged at 40 kt. Epsilon remains a large cyclone with gale-force or tropical-storm-force winds extending outward more than 250 nmi in the northern semicircle. The center has drifted eastward since the last advisory, with the initial motion a somewhat uncertain 075/3. A northward to northwestward motion is expected to begin shortly as Epsilon becomes embedded in a large mid-level low over the central Atlantic. Later today, a mid-level ridge is forecast to build to the north and east of the cyclone, forcing Epsilon generally toward the northwest through about 72 h. After that time, a deep-layer trough and associated frontal system moving eastward into the western Atlantic should cause the cyclone to recurve to the northeast at an increasing forward speed. The guidance is in good agreement with the scenario, and the new forecast track, which has only minor adjustments from the previous track, lies near the various consensus models. On the forecast track, Epsilon should make its closest approach to Bermuda on Friday. There are several conflicting factors in the intensity forecast. First, while the cyclone is expected to move over relatively warm sea surface temperatures, the oceanic heat content along the forecast track drops to low levels after 36 h. Second, while the overall shear is forecast to be light to moderate through the forecast period, Epsilon is interacting with the aforementioned upper-level trough, and the global models suggest it will interact with another trough around the 72 h point. These troughs should provide upper-level divergence to aid strengthening, but also may feed cool and dry air into the cyclone, which would be a negative factor. The intensity guidance continues to show gradual strengthening despite the negative factors, with the global models showing fairy low central pressures during the 72-120 h period. Based on this, the intensity forecast continues to call for Epsilon to become a hurricane, and the new forecast has only minor tweaks from the previous forecast. Extratropical transition will likely be underway by 120 h, but likely will not finish until after the end of the forecast period. 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 20/0900Z 25.6N 54.7W 40 KT 45 MPH 12H 20/1800Z 26.6N 55.6W 45 KT 50 MPH 24H 21/0600Z 27.8N 57.4W 50 KT 60 MPH 36H 21/1800Z 28.5N 59.1W 55 KT 65 MPH 48H 22/0600Z 29.4N 60.1W 60 KT 70 MPH 60H 22/1800Z 30.6N 60.9W 65 KT 75 MPH 72H 23/0600Z 31.6N 61.4W 70 KT 80 MPH 96H 24/0600Z 33.5N 62.0W 75 KT 85 MPH 120H 25/0600Z 38.0N 58.0W 70 KT 80 MPH $$ Forecaster Beven NNNN