Coastal storm to unload inches of rain along Eastern Seaboard

Chris Crawford, of Mount Desert Island, Maine, films the raging surf near Otter Point in Acadia National Park as severe weather associated with storm Lee pounds the region, Saturday, Sept. 16, 2023, in Bar Harbor, Maine. (AP Photo/Robert F. Bukaty)

Drenching rainfall will spread across a large area of the East Coast later this week and into the weekend from a system that AccuWeather forecasters say could become the next named tropical storm of the 2023 Atlantic hurricane season.

Late this week, a low-pressure area will develop off the Atlantic coast of the Southeast, becoming a tropical rainstorm in a zone that AccuWeather hurricane experts have been monitoring since last weekend. 

Will the system become a named tropical storm?

AccuWeather forecasters are warning that this coastal storm will be a tropical rainstorm, and may even strengthen into a depression or subtropical storm.

The next name on the 2023 Atlantic hurricane list is Ophelia.

There will be a short window in which the storm can intensify into an organized tropical system, most likely from Friday into early Saturday. There is plenty of warm water in this area of the Atlantic Ocean, making a tropical depression or tropical storm within reach. However, disruptive wind shear, or changing winds with altitude, may prove to be too much for the storm to overcome.

Whether or not the low becomes an organized tropical system, it will bring impacts, AccuWeather Senior Meteorologist Tyler Roys said. “The storm is likely to bring gusty winds and rounds of heavy rain to much of the East Coast,” he said.

Storm to spread torrential rainfall, coastal hazards

Rain will first impact the Carolinas on Friday, as well as parts of southeastern Virginia and the Delmarva Peninsula. The coastal storm will also create windy conditions for beaches along the Outer Banks, beginning on Friday.

The storm is forecast to strengthen as it moves northward along the Eastern Seaboard, spreading rain and coastal impacts to the north as well.

By the start of the weekend, areas from Wilmington and Raleigh, North Carolina, to New York and Boston should all be on alert for yet another wet day. So far this month, New York City has already recorded 5.35 inches of rain, 125% of the historical average for the entire month with more than a week still to go in September.

Much of the rain from this system will be pulled to the north and east, displacing some of the heaviest precipitation well away from the storm’s center. The heaviest rain on Saturday and Saturday night may be in southern New England, even as the storm still sits off the Carolina coast.

“After all the rain that fell in parts of New England from Hurricane Lee, some areas may be even more prone to flooding as this weekend’s rain unfolds,” Roys explained.

Boston picked up 1.38 inches of rain in the days leading up to and through the duration of Lee’s passing, plus another 1.52 inches of rain on Monday after the storm, adding up to almost 3 inches of rain in just 10 days. To put that into perspective, the historical average rainfall for the entire month of September is 3.56 inches.

Due to recent rain and saturation of the ground, flash flooding will be a concern this weekend across the mid-Atlantic and New England, especially in low-lying and poor-drainage areas.

The strengthening storm will also bring increased onshore winds by Saturday, with gusts of 40-60 mph possible near the coast. Yet another weekend of rough surf, strong rip currents and coastal flooding is possible for the mid-Atlantic and New England beaches. The wind and rain are also likely to cause power outages and disruptions to travel and any outdoor activities.

Not only is the rain expected to target New England on Saturday, but more rain is also in the offing on Sunday.

The speed with which the storm moves to the northeast will determine how long the rainy weather will last this weekend across the Northeast, Roys explained. The longer the storm lingers along the East Coast, the higher the rainfall totals could be this weekend.

“Widespread rainfall amounts of 1-3 inches are possible from eastern North Carolina to New England, with higher rainfall amounts forecast near the coast,” Roys said.

Those higher rainfall amounts are expected to top out in the 4-8 inch range from the Outer Banks of North Carolina into portions of the Delmarva. An AccuWeather Local StormMax™ of 12 inches of rain is also possible, especially if the storm tracks closer to the shoreline.

Source: AccuWeather