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| #1109329 (Received by flhurricane at: 10:57 PM 27.Sep.2022) TCDAT4 Hurricane Ian Discussion Number 20 NWS National Hurricane Center Miami FL AL092022 1100 PM EDT Tue Sep 27 2022 The hurricane continues to have an impressive appearance on satellite imagery, exhibiting considerable deep convection with numerous cloud tops colder than -80C. An Air Force Hurricane Hunter Aircraft recently penetrated the center and found that the central pressure had not fallen since earlier this evening. Based on a blend of SFMR-observed surface winds and 700 mb flight-level winds from the Air Force plane, the current intensity is held at 105 kt for now. Ian has turned slightly to the right and the initial motion is now 015/9 kt. Over the next couple of days, the tropical cyclone should move between the western edge of a subtropical high pressure system and a broad trough over the eastern United States. The dynamical model consensus, TVCN, prediction has again shifted a little to the east, and is just slightly slower on this cycle. Therefore the official track forecast has, again, been shifted a few degrees to the east of the previous one. This does not require any change the watches and warnings over Florida at this time. Ian's outflow is being restricted over the southwestern portion of its circulation by southwesterly upper-tropospheric flow over the Gulf of Mexico. Vertical shear over the hurricane is likely to increase up through landfall. The SHIPS guidance and water vapor imagery suggest that there will also be some dry mid-level air in the vicinity. However, it is expected that this large system will be fairly resilient to the shear and dry air before landfall. Therefore, the official intensity forecast continues to show Ian reaching the coast with category 4 intensity. Since radar imagery indicates that an eyewall replacement is probably underway, this could result in a larger eye evolving overnight. Interests along the Florida west coast in the Hurricane Warning area should be prepared for a large and destructive hurricane, and residents in this area should heed the advice of emergency management officials. Users are reminded to not focus on the exact forecast track as some additional adjustments to the track are possible, and significant wind, storm surge, and rainfall hazards will extend far from the center. Key Messages: 1. Life-threatening storm surge is expected along the Florida west coast where a storm surge warning is in effect, with the highest risk from Naples to the Sarasota region. Residents in these areas should listen to advice given by local officials and follow any evacuation orders for your area. 2. Hurricane-force winds are expected in the hurricane warning area in southwest and west-central Florida beginning Wednesday morning with tropical storm conditions expected overnight. Devastating wind damage is expected near the core of Ian. Residents should rush all preparations to completion. 3. Heavy rainfall will spread across the Florida peninsula through Thursday and reach portions of the Southeast later this week and this weekend. Catastrophic flooding is expected across portions of central Florida with considerable flooding in southern Florida, northern Florida, southeastern Georgia and coastal South Carolina. Widespread, prolonged moderate to major river flooding expected across central Florida. FORECAST POSITIONS AND MAX WINDS INIT 28/0300Z 24.9N 82.9W 105 KT 120 MPH 12H 28/1200Z 26.0N 82.5W 115 KT 130 MPH 24H 29/0000Z 27.2N 81.9W 110 KT 125 MPH...INLAND 36H 29/1200Z 28.2N 81.4W 60 KT 70 MPH...INLAND 48H 30/0000Z 29.3N 80.8W 45 KT 50 MPH...OVER WATER 60H 30/1200Z 30.6N 80.8W 45 KT 50 MPH 72H 01/0000Z 32.7N 81.2W 30 KT 35 MPH...INLAND 96H 02/0000Z 36.0N 82.5W 25 KT 30 MPH...POST-TROP/INLAND 120H 03/0000Z...DISSIPATED $$ Forecaster Pasch |
