000 WTNT42 KNHC 202057 TCDAT2 Hurricane Fiona Discussion Number 26 NWS National Hurricane Center Miami FL AL072022 500 PM EDT Tue Sep 20 2022 Deep convection around Fiona's eye is intense, but is in a rather asymmetrical pattern at this time. Upper-tropospheric outflow remains somewhat restricted over the western semicircle of the system. The last Air Force Hurricane Hunter fix in the center of the hurricane around 17Z showed a slight fall of central pressure from earlier in the day, but the flight-level and SFMR-observed surface winds indicated that the maximum winds were still near 100 kt. This is also in agreement with the latest Dvorak satellite estimates from TAFB and SAB. Another Air Force Hurricane Hunter mission into Fiona is scheduled for 00Z to see if Fiona is strengthening again. Vertical wind shear over Fiona, as diagnosed by the SHIPS model, is predicted to remain moderate for the next few days. However, the hurricane is likely to remain in a moist unstable air mass and over a warm ocean for the next couple of days which is likely to offset the influence of shear. In general, the intensity model guidance continues to show strengthening for about the next 48 hours, and so does the official forecast. Fiona is expected to become a category 4 hurricane in a day or so. By 96 hours, global model guidance indicates that the system will be transformed into a vigorous extratropical cyclone near Atlantic Canada. The hurricane is still headed toward the north-northwest with an initial motion estimate of 330/7 kt. The track forecast scenario is generally unchanged from the previous advisory. Fiona should turn northward while moving along the western side of a mid-level anticyclone during the next day or so. In 2-3 days, an intense mid-tropospheric trough will be moving off the northeast United States coast. This feature should cause Fiona to accelerate toward the north-northeast and northeast during the latter part of the forecast period. The official forecast follows about the same trajectory as the previous one, but is just a tad slower. This is in good agreement with both the simple and corrected consensus predictions. Key Messages: 1. Heavy rains around the center of Fiona will continue to impact the Turks and Caicos through this evening with continued life-threatening flooding. Localized additional flash and urban flooding is possible in Puerto Rico and the Dominican Republic. 2. Hurricane conditions are affecting portions of the Turks and Caicos islands, while tropical storm conditions should affect portions of the southeastern Bahamas during the next few hours. 3. Tropical storm conditions are possible on Bermuda by late Thursday. 4. Fiona is expected to affect portions of Atlantic Canada as a powerful hurricane-force cyclone late Friday and Saturday, and could produce significant impacts from high winds, storm surge, and heavy rainfall. Interests in these areas should closely monitor the progress of Fiona and updates to the forecast. FORECAST POSITIONS AND MAX WINDS INIT 20/2100Z 22.6N 71.8W 100 KT 115 MPH 12H 21/0600Z 23.6N 72.0W 110 KT 125 MPH 24H 21/1800Z 25.0N 71.9W 115 KT 130 MPH 36H 22/0600Z 26.9N 71.3W 115 KT 130 MPH 48H 22/1800Z 29.4N 70.1W 120 KT 140 MPH 60H 23/0600Z 32.4N 67.8W 115 KT 130 MPH 72H 23/1800Z 36.9N 63.5W 105 KT 120 MPH 96H 24/1800Z 46.5N 60.0W 85 KT 100 MPH...POST-TROP/EXTRATROP 120H 25/1800Z 55.0N 58.0W 55 KT 65 MPH...POST-TROP/EXTRATROP $$ Forecaster Pasch