Potential nor'easter could bring rain, wind and flooding to East Coast

A coastal storm could form into a nor'easter this week, bringing gusty winds, rain and potential flooding along the East Coast, forecasters warned on Sept. 21.

There's also a chance that the system could morph into a tropical storm south of New England by the weekend.

The National Weather Service said rain and thunderstorms are expected across the central and eastern United States on Sept. 21 as the storm heads towards the Mid-Atlantic and Northeast around the end of the week. The weather pattern will lead to multiple days of strong onshore winds, which could lead to coastal flooding and beach erosion as the full moon raises the tides, the weather service said.

"After a mostly dry week we are monitoring the potential for a coastal storm to bring rain and strong winds to southern New England around the end of the week," the weather service office in Boston said. "At this point confidence is low in what, if any, impacts will be felt across the region."

Nor'easters are large, intense areas of low pressure that typically develop off the East Coast during the late fall, winter and early spring. The storms earned their name because they usually bring strong northeast winds over the East as they move north along the Atlantic Coast.

The exact track of this storm and the accompanying heavy rains is not yet known, the weather service said, but eastern North Carolina could see increased rain on Sept. 24 before precipitation hits New England on Sept. 25 and 26. Temperatures will be cooler than usual in the East, particularly the Mid-Atlantic, forecasters said.

Forecasters in North Carolina warned hazardous marine conditions could emerge starting on Sept. 23 as large waves bring "dangerous surf conditions, beach erosion and potentially ocean overwash at vulnerable locations along the Outer Banks."

Winds could start picking up in the region late on Sept. 22, though it's too early to say exactly how strong they will be, according to The Weather Channel. Coastal flooding is likely from North Carolina to New York from Sept. 22 through Sept. 25, particularly during high tide, AccuWeather reported.

"The rain could extend far enough north to ease the ongoing drought in Maine," AccuWeather Senior Meteorologist Chad Merrill said. "Regardless of how close to the coast the storm tracks, it has the potential to become strong enough to bring rain and gusty winds in coastal areas, while prolonged rough surf may cause above-normal tides and beach erosion."

Could it transition into a tropical storm? "For now, the system looks to stay non-tropical but there’s a small chance (~20% chance) its core warms enough so that it transitions to a tropical system later this week into the weekend," said hurricane specialist Michael Lowry of WPLG-TV in Miami.

"Both the AI models and traditional, physics-based models agree on this low probability scenario so it’s something to follow," Lowry said. "Regardless, it shouldn’t appreciably change the impacts expected for the coast later this week."