000 WTNT42 KNHC 191459 TCDAT2 Hurricane Fiona Discussion Number 21 NWS National Hurricane Center Miami FL AL072022 1100 AM AST Mon Sep 19 2022 The center of the hurricane is moving off the northern coast of the Dominican Republic near eastern Samana Bay. High-resolution visible satellite imagery from the GOES-16 mesoscale sector show a well-organized system, but the eye is currently cloud-filled. The current intensity and central pressure, 75 kt and 980 mb, are based on the assumption of some weakening and filling due to Fiona's interaction with the land mass of eastern Hispaniola. An Air Force Reserve Unit reconnaissance aircraft is scheduled to investigate the hurricane tonight, assuming that the cyclone will have moved far enough offshore over the waters of the southwestern Atlantic. Fiona is moving northwestward, or at about 310/7 kt. The system is moving along the southwestern periphery of a mid-level high pressure area over the subtropical Atlantic. During the next 2-3 days, the hurricane should gradually turn toward the north-northwest and north as it rounds the western side of the high. Later in the forecast period, a large and strong trough moving over the northeastern United States should cause Fiona to accelerate northeastward and north-northeastward. The official track forecast remains in agreement with the previous NHC solutions and is close to both the simple and corrected dynamical model consensus predictions. Moderate vertical shear associated with southwesterly upper-level flow over Fiona is likely to prevail during the next few days. However, this shear is not expected to be strong enough to offset the favorable thermodynamics over the southwestern Atlantic. The official forecast shows steady strengthening with Fiona becoming a major hurricane within the next couple of days. This is in line with the latest intensity model guidance and also similar to the previous NHC forecasts. As the hurricane accelerates deeper into the mid-latitudes and begins interacting with the strong trough to its west, 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. Heavy rains from Fiona will continue to produce life- threatening and catastrophic flooding along with mudslides and landslides across Puerto Rico through tonight. Life-threatening flash and urban flooding is likely for eastern portions of the Dominican Republic through early Tuesday. 2. Hurricane conditions are occuring across portions of the Dominican Republic within the warning area. Tropical storm conditions will continue on Puerto Rico through this afternoon and over portions of the Dominican Republic within the warning area through tonight. 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 19/1500Z 19.1N 69.2W 75 KT 85 MPH 12H 20/0000Z 20.1N 69.8W 85 KT 100 MPH 24H 20/1200Z 21.5N 70.7W 90 KT 105 MPH 36H 21/0000Z 22.9N 71.2W 95 KT 110 MPH 48H 21/1200Z 24.2N 71.2W 105 KT 120 MPH 60H 22/0000Z 26.0N 70.7W 110 KT 125 MPH 72H 22/1200Z 28.2N 69.9W 110 KT 125 MPH 96H 23/1200Z 33.3N 65.3W 105 KT 120 MPH 120H 24/1200Z 45.0N 57.5W 80 KT 90 MPH $$ Forecaster Pasch