USNA Weather Forecast

Forecast Discussion:

Category 4 Major Hurricane Ian, with 155 mph sustained winds (as of 0800 on 28 September), will make landfall today between Sarasota and Cape Coral/Ft. Meyers, FL. Most of the model guidance now suggests that Ian will track slowly northeastward through Central Florida and gradually weaken over the next 24 to 36 hours, before turning northward into Georgia and South Carolina (potentially emerging into the Atlantic for a brief period of time and making a second landfall as a Tropical Storm or weak Category 1 Hurricane). For information on storm impacts in Florida, Georgia, and South Carolina, please visit the National Weather Service’s (NWS) National Hurricane Center at https://hurricanes.gov/.

The track of Ian through the Southeast U.S. will largely be determined by the strength and position of an area of high pressure building over New England. The current forecast from the NWS National Hurricane Center suggests the center of the storm will likely be near the Blue Ridge Mountains of North Carolina, Tennessee, Kentucky, and Virginia by Saturday night. However, the storm will have likely have diminished into a Post-Tropical Depression by that point, meaning it will no longer have purely tropical characteristics as it interacts with the aforementioned high pressure. This also means the associated precipitation and wind field will likely no longer be concentrated around the center of circulation and will instead spread out toward the north and east, likely into the Mid-Atlantic region. The expectation is for the remnants of Ian to bring rain into Central Maryland sometime on Saturday, but the timing and intensity of precipitation over the weekend remains uncertain. Model guidance suggests that anywhere between 0.25 and 2.0 inches of rainfall is possible through Sunday evening, depending on how the remnants interact with the area of high pressure. It will also be breezy this weekend with northeast winds 10-20 mph, and perhaps gusting as high as 32 mph depending on the track of the system. In terms of coastal flooding, sustained winds out of the northeast have been shown to result in higher than normal water levels in Annapolis, but based on the current storm track, the forecasted wind direction likely will not bring a significant surge of water up the mainstem of the Chesapeake Bay. Minor coastal flooding will therefore be possible around high tides over the weekend, and perhaps into next week even after the northerly wind forcing subsides. Depending on the track, the rain could linger into early next week. The NWS Weather Prediction Center Suggests that a storm totals of over 2.5 inches of rainfall is