It’s a rare phenomenon, but the plume of smoke that nearly obscured the rising sun in the Berkshires on Tuesday was an unwelcome souvenir of the devastating Western wildfires.

The haze is expected to linger at 20,000 to 30,000 feet in altitude until a cold front pushes through Thursday afternoon, clearing the skies, said National Weather Service meteorologist Andrei Evbuoma in Albany, N.Y.

There won’t be any air pollution or public health impact, because the smoke is aloft, high in the atmosphere, he pointed out.

“The only impact will be the milky, hazy, grayish color of the sky,” he said.

A silver lining, he noted, will be “spectacular” sunsets and sunrises through Thursday morning.

“We usually don’t see a cross-country impact," he said. "This was predicted, given how significant the fires are out west, but it’s certainly uncommon.”

National Weather Service satellite photos and animated video on the Albany office’s Facebook page illustrated the huge area affected by two plumes of smoke, including much of the Midwest, and from Washington D.C., to New York, Boston, the rest of New England and into northern Quebec and Nova Scotia.

In California, nearly 17,000 firefighters are battling 29 major wildfires. Since mid-August the blazes have destroyed 4,100 buildings and killed 24 people in the state. Fires have engulfed 3.3 million acres in California this year — desolation greater in size than Connecticut.

Authorities in Oregon say more than 20 people remain missing from the wildfires burning across the state. Gov. Kate Brown said that 10 people are confirmed dead, and that the number likely would rise as more confirmations come in from local law enforcement and medical authorities. Fires also are burning in Washington state, Arizona, Colorado and Idaho.

Information from The Associated Press was included in this article.

Clarence Fanto can be reached at cfanto@yahoo.com, on Twitter @BE_cfanto or at 413-637-2551.