|
Show Selection: |
| #1107839 (Received by flhurricane at: 11:09 PM 18.Sep.2022) TCDAT2 Hurricane Fiona Discussion Number 19 NWS National Hurricane Center Miami FL AL072022 1100 PM AST Sun Sep 18 2022 Radar imagery and recent fixes from an Air Force Reserve Hurricane Hunter aircraft show that Fiona has jogged westward over the Mona Passage, in between Puerto Rico and the Dominican Republic this evening. Radar, microwave imagery, and observations from the aircraft indicate that the eye has become smaller, with the radius of maximum winds decreasing to 10-15 n mi. There has been some warming of the clouds tops in the band just outside the CDO, but the conventional satellite presentation has not changed much since late this afternoon. The aircraft has measured a peak 700-mb flight- level wind of 75 kt, and SFMR winds of around 70 kt. A dropwindsonde in the northwestern eyewall measured a mean wind of 89 kt in the lowest 150 m of the profile, which supports the 75 kt initial intensity. The aircraft just reported a minimum pressure of 982 mb on it latest pass through the center just a short time ago. As mentioned above, Fiona has been moving more westward this evening, but the longer-term motion estimate is 300/9 kt. With this westward jog, the center is likely to make landfall in the eastern portion of the Dominican Republic overnight, and the early portion of the track forecast has been adjusted accordingly. The dynamical model guidance insists that a northwestward motion should begin soon, and the models are in good agreement that Fiona will move around the western periphery of a subtropical ridge over the next several days. Later in the forecast period, Fiona is forecast to accelerate northeastward, and north-northeastward ahead of a trough that is expected to move across the northeastern United States by the end of the week. The official forecast is near the center of the guidance envelope, but is slightly slower than the previous forecast at days 4 and 5 to be closer to the latest consensus aids. Fiona could strengthen slightly within the next few hours before it reaches the coast of the Dominican Republic overnight. After that time, some weakening could occur while the center remains near eastern Hispaniola. Once Fiona moves over the Atlantic waters north of the Dominican Republic, the hurricane will be over warm water and in fairly moist environment. Although there is likely to be some moderate shear over the hurricane, nearly all of the intensity models suggest the cyclone will strengthen, and the official forecast again calls for Fiona to become a major hurricane in a couple of days. The NHC intensity forecast is close to the IVCN intensity aid, and is similar to the previous wind speed forecast. Based on Fiona`s latest forecast track, the government of the Bahamas has issued a Hurricane Warning for the Turks and Caicos Islands. Key Messages: 1. Hurricane conditions are expected to begin in portions of the warning area in the Dominican Republic within the next few hours. Tropical storm conditions will continue to spread over portions of the Dominican Republic within the warning area through Monday. 2. Heavy rains from Fiona will continue across Puerto Rico overnight tonight and spread over the Dominican Republic through Monday. These rains will continue to produce life-threatening and catastrophic flash 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. Hurricane conditions are expected in portions of the Turks and Caicos Islands on Tuesday, and tropical storm conditions are expected in the southeastern Bahamas by late Monday or early Tuesday. FORECAST POSITIONS AND MAX WINDS INIT 19/0300Z 18.0N 68.1W 75 KT 85 MPH 12H 19/1200Z 19.0N 69.1W 80 KT 90 MPH 24H 20/0000Z 20.4N 70.0W 90 KT 105 MPH 36H 20/1200Z 21.9N 70.8W 95 KT 110 MPH 48H 21/0000Z 23.3N 71.1W 100 KT 115 MPH 60H 21/1200Z 24.7N 71.1W 105 KT 120 MPH 72H 22/0000Z 26.4N 70.5W 110 KT 125 MPH 96H 23/0000Z 31.2N 67.4W 110 KT 125 MPH 120H 24/0000Z 40.3N 59.8W 95 KT 110 MPH $$ Forecaster Brown |
