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| #1023815 (Received by flhurricane at: 3:47 PM 03.Nov.2020) TCDAT4 Hurricane Eta Discussion Number 13 NWS National Hurricane Center Miami FL AL292020 400 PM EST Tue Nov 03 2020 After meandering just offshore of the coast of northeastern Nicaragua this morning, the eye of Eta began moving westward and is currently making landfall along the coast of Nicaragua about 15 n mi south of Puerto Cabezas. Visible satellite imagery has shown that the eye of Eta became larger as the hurricane completed an eyewall replacement. A blend of the earlier aircraft data and recent subjective and objective satellite intensity estimates yields an initial intensity of 120 kt. Eta remains an extremely dangerous category 4 hurricane, and is likely producing a very high storm surge and catastrophic damage. In addition, the slow-moving system is likely to produce torrential rains and inland flooding that will continue to be an extremely serious threat over the next couple of days. Once the eyewall is fully onshore, rapid weakening should begin, and Eta is forecast to weaken to a tropical storm by early Wednesday, and become a tropical depression Wednesday night. Although it appears unlikely that the surface circulation will remain intact while Eta moves over Central America, most of the global model guidance indicates that the low-level vorticity center will emerge over the northwestern Caribbean Sea within 60-72 hours. At that time, the system is forecast to interact with an upper-level trough over the northern Gulf of Mexico, and re-development later in the period appears likely with some strengthening by days 4 and 5. Due the interaction with the upper-level trough, the system is likely to have a more hybrid or subtropical structure late in the period. Eta appears to be moving westward at about 4 kt. A ridge to the north of the hurricane should steer the system westward to west- northwestward at a faster forward speed over the next couple of days. By late in the week, Eta or its remnants should turn northward, and then northeastward around the southeastern portion of the aforementioned trough. Although the 12z GFS and ECMWF models are in general agreement on the overall forecast scenario, there are large differences in how fast Eta accelerates northeastward. The NHC track forecast is near the HFIP corrected consensus model which lies between the faster GFS and slower ECMWF solutions. There is still significant spread among the various global models and the ensembles, which results in a higher than normal level of uncertainty regarding the details of the track and intensity forecast later in the period. Key Messages: 1. Catastrophic wind damage is expected during the next few hours as Eta's eyewall moves onshore along the northeastern coast of Nicaragua. 2. A catastrophic and life-threatening storm surge, along with destructive waves, are expected along portions of the northeastern coast of Nicaragua near and to the north of where the center has crossed the coast. Water levels could reach as high as 14 to 21 feet above normal tide levels in some parts of the hurricane warning area. 3. Through Friday evening, 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. 4. Eta is forecast to regain tropical storm strength as 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 03/2100Z 13.8N 83.5W 120 KT 140 MPH 12H 04/0600Z 13.8N 84.2W 75 KT 85 MPH...INLAND 24H 04/1800Z 14.1N 85.5W 40 KT 45 MPH...INLAND 36H 05/0600Z 14.7N 87.2W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 05/1800Z 15.4N 88.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 60H 06/0600Z 16.3N 88.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 06/1800Z 17.0N 87.7W 30 KT 35 MPH...OVER WATER 96H 07/1800Z 20.0N 83.5W 40 KT 45 MPH 120H 08/1800Z 24.0N 80.5W 45 KT 50 MPH $$ Forecaster Brown |