000 WTNT44 KNHC 041459 TCDAT4 Tropical Storm Eta Discussion Number 16 NWS National Hurricane Center Miami FL AL292020 900 AM CST Wed Nov 04 2020 Eta is weakening as it moves across northern Nicaragua, Most of the inner core convection has weakened, and the strongest convection is now in bands well removed from the center. There are no wind observations available near the center of Eta at this time, so the initial intensity is reduced to a uncertain 45 kt. The initial motion is westward or 275/6. A mid-level ridge to the north of the cyclone should steer it on a generally west-northwestward track during the next 36 h or so. After that time, a mid- to upper-level trough moving over the central and eastern Gulf of Mexico is expected to cause Eta or is remnants to turn northward and then northeastward, Then, by 120 h, the cyclone is likely to move northward on the eastern side of the trough. While the track guidance is in reasonable agreement with this scenario, there is some spread on when and where the various turns will occur, and thus there is a fair amount of uncertainty about what parts of Cuba and Florida the center may pass near or over. The new forecast track is similar to the previous track and lies near the various consensus models. Eta will continue to weaken while it crosses Nicaragua and Honduras, and it is expected to decay to a remnant low before it reaches the Gulf of Honduras or the northwestern Caribbean Sea. Re-development is expected once the center is over the water. However, interaction with the aforementioned trough could result in a structure that is more subtropical or hybrid, as indicated by the GFS/HWRF, than a classical tropical cyclone, as suggested by the ECMWF. The new intensity forecast will follow the previous forecast and go with a gradual intensification in the expectation that the GFS scenario is more likely to verify, However, the intensity forecast lies a little below the intensity consensus. Although it is weakening, Eta will continue to produce heavy rainfall and flooding over portions of Central America. Key Messages: 1. Through Sunday morning, heavy rainfall from Eta will lead to catastrophic, life-threatening flash flooding and river flooding across portions of Central America, along with landslides in areas of higher terrain. Flash and river flooding is also possible across Jamaica, southeast Mexico, El Salvador, southern Haiti, and the Cayman Islands. 2. Eta is forecast to regain tropical storm strength before it moves across portions of Cuba and approaches southern Florida this weekend. While it is too soon to determine the exact timing, magnitude, and location of possible impacts from wind and rainfall, interests in Cuba, southern Florida and the Florida Keys should monitor the progress of Eta through the week. FORECAST POSITIONS AND MAX WINDS INIT 04/1500Z 13.9N 85.2W 45 KT 50 MPH...INLAND 12H 05/0000Z 14.1N 86.3W 30 KT 35 MPH...INLAND 24H 05/1200Z 14.9N 87.7W 25 KT 30 MPH...INLAND 36H 06/0000Z 16.0N 88.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 06/1200Z 17.0N 88.2W 30 KT 35 MPH...OVER WATER 60H 07/0000Z 18.0N 86.4W 35 KT 40 MPH 72H 07/1200Z 19.6N 84.4W 40 KT 45 MPH 96H 08/1200Z 23.0N 81.5W 45 KT 50 MPH 120H 09/1200Z 25.0N 82.0W 50 KT 60 MPH $$ Forecaster Beven