000 WTNT42 KNHC 182059 TCDAT2 Hurricane Fiona Discussion Number 18 NWS National Hurricane Center Miami FL AL072022 500 PM AST Sun Sep 18 2022 The eye of Fiona made landfall over extreme southwestern Puerto Rico around 1920 UTC, and the center of the hurricane is now moving into the Mona Passage between Puerto Rico and the Dominican Republic. Earlier observations from Hurricane Hunter aircraft and WSR-88D radar velocity data indicate that the maximum winds were near 75 kt. Since there has been little change in the organization of the system since the aircraft missions earlier today, the intensity is kept at that value for now. A NOAA Saildrone went through the eye of Hurricane Fiona earlier today and the data from that vessel indicated a minimum central pressure of 986 mb. Another Air Force Hurricane Hunter mission into Fiona is scheduled for this evening. The hurricane will be moving through a fairly moist air mass and over SSTs warmer than 29 deg C for the next few days. It should be noted that the SHIPS output shows 15-20 kt of vertical wind shear over Fiona for the next several days. However that same guidance model shows steady strengthening with the system becoming a major hurricane in about 48 hours. Based on the bulk of the numerical guidance, the official intensity forecast is increased slightly from the previous NHC prediction, and is near or a little below the model consensus. Center fixes indicate that Fiona's motion is between west-northwest and northwest, or about 305/8 kt. There has been little change to the track model guidance, which is fairly tightly clustered albeit with some differences in forward speed. The cyclone should move along the western periphery of a subtropical high pressure area for the next 3-4 days. Later in the forecast period, Fiona is expected to accelerate northeastward and north-northeastward as it encounter the faster high-latitude flow. The official track forecast has not been changed significantly, and remains in close agreement with the TVCA dynamical model. Key Messages: 1. Hurricane conditions are expected to begin in portions of the warning area in the Dominican Republic tonight and Monday. Tropical storm conditions will reach the Dominican Republic this evening. 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 catastrophic 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 expected in the Turks and Caicos Islands and the southeastern Bahamas by late Monday or early Tuesday. FORECAST POSITIONS AND MAX WINDS INIT 18/2100Z 18.2N 67.3W 75 KT 85 MPH 12H 19/0600Z 18.7N 68.2W 80 KT 90 MPH 24H 19/1800Z 20.0N 69.2W 85 KT 100 MPH 36H 20/0600Z 21.4N 70.1W 90 KT 105 MPH 48H 20/1800Z 22.8N 70.8W 100 KT 115 MPH 60H 21/0600Z 24.1N 70.9W 105 KT 120 MPH 72H 21/1800Z 25.7N 70.7W 110 KT 125 MPH 96H 22/1800Z 30.0N 68.5W 105 KT 120 MPH 120H 23/1800Z 37.5N 61.5W 95 KT 110 MPH $$ Forecaster Pasch