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Hurricane Eta Forecast Discussion Number 9
2020-11-02 21:52:52| National Hurricane Center (Atlantic)
Issued at 400 PM EST Mon Nov 02 2020 000 WTNT44 KNHC 022052 TCDAT4 Hurricane Eta Discussion Number 9 NWS National Hurricane Center Miami FL AL292020 400 PM EST Mon Nov 02 2020 Eta is an extremely impressive hurricane in both visible and infrared satellite imagery. The hurricane has a very small eye that is located within a symmetric Central Dense Overcast with cloud top temperatures below -80C. Although objective Dvorak estimates are lower due to the technique's difficulty in analyzing the correct scene type because of the pinhole eye, data T-numbers from both TAFB and SAB analysts reached 6.0 on the Dvorak scale at 18Z, which equates to a wind speed of 115 kt. A recent UW/CIMSS SATCON intensity estimate also supports category 4 intensity. As mentioned in previous advisories over the past 24 hours, the environment ahead of Eta is forecast to remain quite favorable with low vertical wind shear and warm sea surface temperatures. These conditions should allow for additional strengthening, however a difficult-to-predict eyewall replacement cycle could begin at any time which could cause Eta's intensity to begin to level off. Since there are no signs of an eyewall replacement yet, the updated NHC intensity forecast calls for continued rapid strengthening for another 6 to 12 hours, and it is again at the upper-end of the guidance envelope. After landfall, Eta should quickly weaken while it moves over the mountainous terrain of Central America. The hurricane has turned west-southwestward with an initial motion estimate of 255/8 kt. The track forecast reasoning is unchanged from this morning. A mid-level ridge over the south-central United States should steer Eta west-southwestward toward the coast of Nicaragua with the hurricane making landfall tonight or early Tuesday. After landfall, Eta is forecast to turn westward, and then west-northwestward while it moves over Central America through midweek. Eta's surface circulation may not survive its trek over the mountainous terrain of Central America, but most of the global models continue to depict a cyclone over the northwestern Caribbean Sea by later this week and into the weekend which appears to develop from at least a part of Eta's remnants. Therefore, the NHC track forecast continues to show the system emerging over the northwestern Caribbean late in the period, however the long range portion of the forecast remains quite uncertain. Since Eta is likely to be a very slow-moving system after it makes landfall in Central America, torrential rains and flooding will be a major threat. Key Messages: 1. Catastrophic wind damage is expected where Eta's eyewall moves onshore along the northeastern coast of Nicaragua tonight or early Tuesday. Tropical storm force winds are beginning to reach the coast within the Hurricane Warning area in Nicaragua, and residents there should have completed their preparations. A Tropical Storm Warning is also in effect for the northeastern coast of Honduras. 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 makes landfall. Water levels could reach as high as 12 to 18 feet above normal tide levels in some parts of the hurricane warning area. Preparations to protect life and property should now be complete. 3. Through Friday evening, heavy rainfall from Eta will likely 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. FORECAST POSITIONS AND MAX WINDS INIT 02/2100Z 14.5N 82.3W 115 KT 130 MPH 12H 03/0600Z 14.1N 83.1W 130 KT 150 MPH 24H 03/1800Z 14.0N 83.7W 90 KT 105 MPH...INLAND 36H 04/0600Z 14.0N 84.5W 45 KT 50 MPH...INLAND 48H 04/1800Z 14.2N 85.5W 30 KT 35 MPH...INLAND 60H 05/0600Z 14.7N 86.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 05/1800Z 15.5N 88.3W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 06/1800Z 16.7N 88.1W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 07/1800Z 18.0N 86.0W 30 KT 35 MPH...TROPICAL DEPRESSION $$ Forecaster Brown/Berg
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