000 WTNT42 KNHC 190856 TCDAT2 Hurricane Fiona Discussion Number 20 NWS National Hurricane Center Miami FL AL072022 500 AM AST Mon Sep 19 2022 Fiona strengthened before making landfall as an 80-kt hurricane in the Dominican Republic to the south-southwest of Punta Cana around 0730 UTC this morning. Data from the Air Force Hurricane Hunters around 0500 UTC indicated a closed eye, with a minimum pressure that had fallen to 979 mb. Soon thereafter, the eye cleared out in infrared satellite imagery and the inner core structure improved in NWS San Juan radar data. The center of Fiona is currently inland over the eastern Dominican Republic, but radar data indicate that the outer rainbands of Fiona continue to move northward across Puerto Rico. The initial intensity is 80 kt for this advisory. Although the longer-term motion of Fiona is west-northwestward, the center has been moving more northwestward (310/7 kt) over the past few hours. This motion should continue as Fiona crosses the eastern portion of the Dominican Republic this morning and then emerges into the southwestern Atlantic. After moving away from land, the tightly clustered track guidance shows Fiona turning north-northwestward and northward through midweek around the western extent of a subtropical ridge. Then, an acceleration to the north-northeast is forecast late this week as Fiona moves within the flow ahead of an amplifying deep-layer trough that will move off the northeastern U.S. coast. The NHC track forecast remains very close to the previous one and lies near the center of the guidance envelope. It is, however, a bit slower with the recurvature of Fiona later this week, as reflected in the latest consensus aids. As the center of Fiona crosses the Dominican Republic, land interaction may briefly disrupt the organization of the hurricane and result in some short-term weakening. However, as Fiona moves away from land, more significant strengthening is expected while it moves across SSTs greater than 29C within a fairly moist and unstable environment over the western Atlantic. The latest intensity guidance unanimously calls for strengthening during the next few days, and the latest NHC forecast generally falls between the IVCN and HCCA aids. This brings Fiona up to major hurricane strength by Wednesday. As the hurricane accelerates deeper into the mid-latitudes and begins interacting with a deep-layer trough, it is expected to begin extratropical transition by day 5, although the process will likely not be completed until after the end of the forecast period. Key Messages: 1. Hurricane conditions are spreading across portions of the Dominican Republic within the warning area. Tropical storm conditions will continue on Puerto Rico through this morning and over portions of the Dominican Republic within the warning area through tonight. 2. Heavy rains from outer bands of Fiona will continue across Puerto Rico into this afternoon. The center of Fiona will persist over eastern Dominican Republic into this afternoon with heavy bands then lasting through tonight. These rainfall amounts will continue to produce life-threatening and catastrophic flooding along with mudslides and landslides across Puerto Rico. Life-threatening flash and urban flooding is likely for eastern portions of the Dominican Republic. 3. Fiona is forecast to strengthen after moving away from Puerto Rico and the Dominican Republic. Hurricane conditions are expected in the Turks and Caicos on Tuesday, and tropical storm conditions are expected in the southeastern Bahamas by late Monday or early Tuesday. FORECAST POSITIONS AND MAX WINDS INIT 19/0900Z 18.5N 68.6W 80 KT 90 MPH...INLAND 12H 19/1800Z 19.4N 69.3W 80 KT 90 MPH...NEAR THE COAST 24H 20/0600Z 20.8N 70.3W 90 KT 105 MPH 36H 20/1800Z 22.2N 71.0W 95 KT 110 MPH 48H 21/0600Z 23.6N 71.2W 100 KT 115 MPH 60H 21/1800Z 25.1N 70.9W 105 KT 120 MPH 72H 22/0600Z 27.0N 70.2W 110 KT 125 MPH 96H 23/0600Z 32.5N 66.5W 110 KT 125 MPH 120H 24/0600Z 42.5N 58.5W 95 KT 110 MPH $$ Forecaster Reinhart