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#1025437 (Received by flhurricane at: 9:42 AM 15.Nov.2020) TCDAT1 Hurricane Iota Discussion Number 9 NWS National Hurricane Center Miami FL AL312020 1000 AM EST Sun Nov 15 2020 Iota continues to rapidly strengthen. The hurricane has an impressive appearance in visible satellite imagery with a very symmetric Central Dense Overcast and excellent banding features in all quadrants. The outflow has become well established and recent microwave satellite imagery has shown a 37-GHz eye feature and a mid-level eye that was not quite closed. A TAFB Dvorak classification of T4.5 was the basis for the 75-kt 1200 UTC analyzed intensity, and with the continued improvement in structure the advisory wind speed is set at 80 kt. An Air Force Reserve Hurricane Hunter aircraft is currently en route to the storm. Iota is located within an extremely conducive environment for strengthening. The upper-level wind pattern is forecast to remain quite favorable while the storm crosses sea surface temperatures of 28.5-29 degrees C. As a result, continued rapid strengthening is expected during the next 24 to 36 hours, and Iota is forecast to become a potentially catastrophic category 4 hurricane before it reaches the coast of northeastern Nicaragua or eastern Honduras. A difficult-to-predict eyewall replacement cycle could cause the intensity to begin to level off when Iota nears the coast. The new NHC intensity forecast calls for continued rapid strengthening and is in good agreement with the SHIPS and HFIP corrected consensus models. After landfall, rapid weakening should occur as Iota moves over the mountainous terrain of Central America. The hurricane has begun moving faster toward the west-northwest, with a long-term motion estimate of 285/8 kt. The steering currents ahead of Iota are well established as a strong mid-level ridge is located over the western Atlantic and Florida. This should keep Iota on a westward to west-northwestward heading through landfall. After landfall, a westward to west-southwestward track is anticipated. The global models are in good agreement on this scenario and the updated NHC track forecast is only adjusted a little north of the previous track to be closer to the latest multi-model consensus aids. Key Messages: 1. Iota is expected to continue to rapidly intensify and be an extremely dangerous category 4 hurricane when it approaches the coast of Central America on Monday. Potentially catastrophic winds and a life-threatening storm surge are expected along portions of the coast of northeastern Nicaragua and eastern Honduras where a hurricane warning is in effect. 2. Hurricane conditions are expected and storm surge impacts are possible on Providencia tonight and Monday. Tropical storm conditions are expected and hurricane conditions are possible by this evening on San Andres. 3. Through Thursday, heavy rainfall from Iota will likely lead to life-threatening flash flooding and river flooding across portions of northern Colombia and Central America. Flooding and mudslides in Honduras and Nicaragua could be exacerbated by Hurricane Etas recent effects there, resulting in significant to potentially catastrophic impacts. FORECAST POSITIONS AND MAX WINDS INIT 15/1500Z 13.3N 78.5W 80 KT 90 MPH 12H 16/0000Z 13.8N 79.7W 95 KT 110 MPH 24H 16/1200Z 14.2N 81.4W 110 KT 125 MPH 36H 17/0000Z 14.4N 82.9W 120 KT 140 MPH 48H 17/1200Z 14.5N 84.3W 80 KT 90 MPH...INLAND 60H 18/0000Z 14.4N 85.5W 45 KT 50 MPH...INLAND 72H 18/1200Z 14.3N 86.8W 30 KT 35 MPH...INLAND 96H 19/1200Z 13.8N 89.8W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 20/1200Z...DISSIPATED $$ Forecaster Brown |