000 WTNT42 KNHC 181453 TCDAT2 Hurricane Fiona Discussion Number 17 NWS National Hurricane Center Miami FL AL072022 1100 AM AST Sun Sep 18 2022 Observations from Air Force and NOAA Hurricane Hunter aircraft and Doppler velocities from the San Juan WSR-88D radar indicate that Fiona is strengthening, and is now a hurricane. The aircraft and radar data support a current intensity of 70 kt. Satellite imagery shows an expanding upper-level outflow pattern over the system. Fiona should be moving in an environment of moderate vertical shear, over warm SSTs, and within a fairly moist air mass for the next few days. The only obvious impediments to strengthening should be the interaction with the land masses of Puerto Rico and Hispaniola during the next day or so. The official forecast is above the previous one, but still a little below the model consensus. It appears likely that Fiona will become the first major hurricane of this Atlantic season in a few days. Although the movement has still been a little irregular based on recent aircraft center fixes, a smoothed initial motion is still west-northwestward, or 285/7 kt. There has been little change to the track forecast reasoning. Over the next few days, the hurricane should move along the western periphery of a mid-tropospheric anticyclone. Thereafter, Fiona is likely to turn north-northeastward and accelerate later in the forecast period as it comes under the influence of higher-latitude westerlies. The official forecast is just a little bit to the left of, and slightly slower than, the previous NHC track during the first 12 to 24 hours and very close to it thereafter. This is very similar to the latest dynamical model consensus aid, TVCA. Key Messages: 1. Hurricane conditions are expected across portions of Puerto Rico today and in portions of the Dominican Republic tonight and Monday. Tropical storm conditions are occurring across the U.S. and British Virgin Islands and will reach the Dominican Republic later today and tonight. 2. Heavy rains from Fiona will continue across Puerto Rico through tonight and occur over the Dominican Republic later today into Monday. These rainfall amounts will produce life-threatening flash floods and urban flooding across Puerto Rico and portions of the eastern Dominican Republic, along with mudslides and landslides in areas of higher terrain. 3. Fiona is forecast to continue to strengthen after moving away from Puerto Rico and the Dominican Republic. Tropical storm conditions are possible in the Turks and Caicos Islands and the southeastern Bahamas by late Monday or early Tuesday. FORECAST POSITIONS AND MAX WINDS INIT 18/1500Z 17.3N 66.5W 70 KT 80 MPH 12H 19/0000Z 17.9N 67.3W 75 KT 85 MPH 24H 19/1200Z 18.9N 68.4W 75 KT 85 MPH 36H 20/0000Z 20.3N 69.3W 80 KT 90 MPH 48H 20/1200Z 21.8N 70.1W 90 KT 105 MPH 60H 21/0000Z 23.2N 70.6W 95 KT 110 MPH 72H 21/1200Z 24.6N 70.6W 100 KT 115 MPH 96H 22/1200Z 28.5N 69.3W 100 KT 115 MPH 120H 23/1200Z 34.8N 64.4W 100 KT 115 MPH $$ Forecaster Pasch