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| #1107542 (Received by flhurricane at: 10:51 PM 16.Sep.2022) TCDAT2 Tropical Storm Fiona Discussion Number 11 NWS National Hurricane Center Miami FL AL072022 1100 PM AST Fri Sep 16 2022 The center of Fiona moved across the island of Guadeloupe a few hours ago and it is now over the far northeastern Caribbean Sea. Deep convection has been increasing near the center, and reports from the Air Force Hurricane Hunters indicate that Fiona is a little stronger. The maximum SFMR winds recorded on the flight so far were 50 kt and peak flight-level winds measured were 61 kt. This supports nudging the initial intensity back up to 50 kt. The minimum pressure of 1002 mb is based on a surface observation from Guadeloupe. Tropical-storm-force winds and heavy rains are expected to continue across the Leeward Islands through Saturday afternoon. Fiona continues to move just north of due west, or 280 degrees, at 13 kt on the south side of a deep-layer ridge. A west to west-northwest motion is expected during the next day or so, and that should take Fiona near the Virgin Islands and Puerto Rico during that time. The cyclone is expected to slow down and make a turn to the northwest when it is near or over the Dominican Republic on Monday as it moves toward a weakness in the ridge. A northward motion near the southeastern Bahamas is expected during the early and middle portions of next week. The models generally show a similar theme, but there are notable differences in where, when, and how sharply Fiona makes the northwestward and northward turns. The NHC track forecast is essentially the same as the previous one through 60 h, but a touch to the east of the previous track from days 3 to 5. This forecast lies close to the various consensus aids. Fiona is still feeling some effects of westerly vertical wind shear and dry air entrainment, but the models suggest that the storm could be moving into a region of higher moisture and slightly less shear. These conditions should support slow strengthening and Fiona could be near hurricane strength when it approaches the Dominican Republic. Some weakening is expected due to the interaction with the mountainous terrain of Hispaniola, but re-strengthening is forecast when it moves north of that island. Fiona is expected to reorganize over the southwestern Atlantic and become a hurricane in about 4 days with additional strengthening after that. The NHC intensity forecast is a little higher than the previous one at days 4 and 5, but still below the IVCN and HCCA models. Key Messages: 1. Tropical storm conditions will continue to affect portions of the Leeward Islands through Saturday morning. Tropical storm conditions will spread westward across the U.S. and British Virgin Islands on Saturday and Puerto Rico late Saturday and Saturday night. Tropical storm conditions are possible over Dominica overnight. 2. Heavy rains from Fiona are beginning in the Leeward Islands, and will spread to the British and U.S. Virgin Islands and Puerto Rico Saturday, reaching the Dominican Republic Sunday, and Haiti and the Turks and Caicos Monday through Tuesday. This rainfall may produce considerable flood impacts including flash and urban flooding, along with mudslides in areas of higher terrain. 3. Fiona is expected to strengthen gradually over the northeastern Caribbean Sea, and it could be near hurricane strength as it approaches the southern or eastern coast of the Dominican Republic Sunday afternoon. A Tropical Storm Warning has been issued for portions of the island and additional watches or warnings could be required on Saturday. 4. Fiona is forecast to strengthen after moving across Hispaniola early next week, and interests in the Turks and Caicos Islands and southeastern Bahamas should continue to monitor forecasts for the storm. FORECAST POSITIONS AND MAX WINDS INIT 17/0300Z 16.6N 62.2W 50 KT 60 MPH 12H 17/1200Z 17.0N 63.9W 55 KT 65 MPH 24H 18/0000Z 17.4N 65.8W 55 KT 65 MPH 36H 18/1200Z 17.8N 67.4W 55 KT 65 MPH 48H 19/0000Z 18.4N 68.6W 60 KT 70 MPH...INLAND 60H 19/1200Z 19.4N 69.6W 55 KT 65 MPH...OVER WATER 72H 20/0000Z 20.4N 70.5W 60 KT 70 MPH 96H 21/0000Z 22.3N 71.8W 65 KT 75 MPH 120H 22/0000Z 24.7N 72.0W 75 KT 85 MPH $$ Forecaster Cangialosi |
