Roaring winds will follow the passage of a cold front in the Northeast and Mid-Atlantic on Friday, after the chance of isolated severe thunderstorms late Thursday. Gusts could approach 50 mph in spots at a time of year when trees are fully leafed, boosting the risk of power outages and stirring up loose outdoor objects.

The National Weather Service issued high wind watches for Northern Virginia, the District, much of Maryland and the northern half of the Delmarva Peninsula through eastern Pennsylvania and most of New Jersey.

“Damaging winds could blow down trees and power lines,” the Weather Service in State College, Pa., wrote. “Widespread power outages are possible.”

The strongest winds will occur between Friday afternoon and evening, first arriving along the Blue Ridge and in interior Pennsylvania before spreading across the Interstate 95 corridor and eventually the northern Delmarva and coastal New Jersey.

Scattered storms late Thursday ahead of widespread wind threat

Before Friday’s winds, scattered showers and storms are anticipated in the northern Mid-Atlantic and Northeast late Thursday and Thursday night, which could be locally intense.

At midday on Thursday, a cold front stretched from a low-pressure center near Scranton, Pa., southwestward toward Louisiana. That front touched off damaging thunderstorms on Wednesday, which produced hail larger than baseballs in Oklahoma and Texas and racked up a price tag that will likely top $1 billion.

Heavy rain pooling along the front triggered flooding with more than half a foot in spots. Now, the risk of isolated severe weather continues as the front pushes east.

On Thursday, the National Weather Service Storm Prediction Center outlined much of the zone from eastern Texas to southern New York, including northern Maryland and much of Pennsylvania and New Jersey, in a level 1 out of 5 “marginal risk” for severe weather. While widespread storms are not expected, a couple of cells that develop could mix down sporadic strong wind gusts.

While showers and storms will be hit or miss, as the cold front passes, the air mass over much of the Mid-Atlantic and Northeast will change dramatically, from warm and humid to cool and dry. Dew points, an indicator of humidity, will drop from the tropical, summerlike 60s to the winterlike 20s between Thursday afternoon and Friday night.

Inside Friday’s wind threat

The cold front, drawing in the noticeably drier air, will push through the Interstate 95 corridor between midnight and 4 a.m. Friday.

That dry, dense air will rush southeast into the Mid-Atlantic and Northeast, bringing sustained winds of 20 to 30 mph with gusts up to 50 mph and locally stronger in the high terrain and near the coastline. Winds will really kick up after breakfast on Friday, first to the west and eventually along I-95.

“We are very bullish on advisory level gusts across most of [area],” the Weather Service wrote in State College, Pa.

Atop the Blue Ridge, a few gusts to 55 mph are possible, with 50 mph gusts in the higher elevations near the Mason-Dixon Line. Gusts of 50 to 60 mph are also possible in the Catskills and Adirondacks, particularly along and west of the Hudson Valley. The Delaware and New Jersey beaches could also see gusts top 50 mph.

New York, Baltimore, Philadelphia and Washington, D.C., can all expect gusts of at least 40 mph.

“We could encounter frequent sustained northwest winds of 20 to 35 mph with gusts 45 to 60 mph,” wrote the Weather Service office serving the Washington-Baltimore region. “This magnitude of wind could bring down small branches and blow loose objects around.”

Winds will last until midnight, and only fade after sunrise Saturday.

The gusts could produce minor wind damage, especially since fully-leafed trees will be more susceptible to damage than during the wintertime.

Pattern change and storm potential next week

After a weekend characterized by cooler and drier air settling over the Eastern Seaboard, humidity will begin to return late Sunday into Monday as high pressure shifts offshore and winds turn southerly. That will set the stage for showers and thunderstorms early next week.

While details are hazy at best, atmospheric parameters may support the potential development of strong to severe thunderstorms in the Northeast and Mid-Atlantic around Tuesday, which would reintroduce the chance of strong winds to the forecast.

Jason Samenow contributed to this report.