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| #1023505 (Received by flhurricane at: 3:51 AM 01.Nov.2020) TCDAT4 Tropical Storm Eta Discussion Number 3 NWS National Hurricane Center Miami FL AL292020 400 AM EST Sun Nov 01 2020 Eta has not become appreciably better organized over the past few hours. A large convective band is evident well to the east and northeast of the estimated center, but this band does not have much curvature at this time. A small burst of deep convection is occurring near or over the center, which is likely the early stages of the development of a Central Dense Overcast. Currently, there is a significant amount of lightning in the outer band but little lightning near the center. The intensity is held at 35 kt for this advisory, in agreement with Dvorak estimates from TAFB and SAB. Eta will be moving over very warm waters of SSTs above 29 deg C and in an environment of fairly light vertical shear. Therefore, strengthening is likely. The official forecast, like the previous ones, calls for the cyclone to become a hurricane before approaching Central America. There is also a possibility of rapid strengthening, as suggested by the SHIPS Rapid Intensification Index. The NHC intensity forecast is very similar to the latest corrected consensus prediction up to the expected landfall and follows the Decay-SHIPS guidance after that point. The center location is somewhat uncertain, and my best estimate of initial motion is about the same as before, or 275/13 kt. The track forecast reasoning has not changed significantly. A mid-level ridge to the north and northwest of Eta should cause a westward or west-southwestward motion for the next few days. This would take the cyclone inland over Central America in 72 hours or so. The official track forecast is similar to the previous one, and lies near the simple model consensus and a little north of the corrected consensus. Key Messages: 1. Eta is expected to strengthen to a hurricane early next week as it approaches the coast of Central America early Tuesday, and there is a risk of storm surge, hurricane-force winds, and heavy rainfall for portions of Nicaragua and Honduras, where Hurricane Watches have been issued. Hurricane warnings could be needed for portions of those areas later today. 2. Through Thursday afternoon, heavy rainfall from Eta may lead to life-threatening flash flooding and river flooding, along with landslides in areas of higher terrain across portions of Jamaica, the Cayman Islands, the southern coast of Hispaniola, northern Honduras and northern Nicaragua. FORECAST POSITIONS AND MAX WINDS INIT 01/0900Z 15.2N 75.7W 35 KT 40 MPH 12H 01/1800Z 15.3N 77.7W 45 KT 50 MPH 24H 02/0600Z 15.3N 79.7W 55 KT 65 MPH 36H 02/1800Z 15.1N 81.2W 65 KT 75 MPH 48H 03/0600Z 14.7N 82.2W 75 KT 85 MPH 60H 03/1800Z 14.4N 83.0W 80 KT 90 MPH 72H 04/0600Z 14.2N 83.7W 60 KT 70 MPH...INLAND 96H 05/0600Z 14.3N 85.7W 30 KT 35 MPH...INLAND 120H 06/0600Z 15.0N 87.5W 25 KT 30 MPH...INLAND $$ Forecaster Pasch |