Emily Mae Czachor is a reporter and news editor at CBSNews.com. She typically covers breaking news, extreme weather and issues involving social justice. Emily Mae previously wrote for outlets like the Los Angeles Times, BuzzFeed and Newsweek.

Some Pacific Northwesterners woke Tuesday to an unusual sight: A smoky haze shrouded Mount St. Helens, the large, active stratovolcano in Washington state that erupted catastrophically in 1980. But a new eruption was not to blame for the foggy scene this week, scientists said. Instead, ash from the blast that occurred 45 years ago had suddenly begun to swirl around the mountain.

Strong winds in the area caused the decades-old debris to circulate, according to the United States Geological Survey and forecasters in Portland, which is about 50 miles away from the summit of Mount St. Helens across the Oregon border.

"Mt. Saint Helens is NOT erupting," Portland's National Weather Service office assured in a social media post Tuesday. "Volcanic Ash from the 1980s is being lofted back into the air from the strong east winds."

In live footage that USGS shares online, thick smoke-like clouds appeared to rise from the ground surrounding Mount St. Helens early Tuesday morning, obscuring the mountain and lingering for the remainder of the day. A screenshot from the footage that shows the volcano in clearer weather is posted beside the live video as a comparison.

USGS issued an advisory at around 10:45 a.m. Pacific Time on Tuesday that acknowledged the whirl of old volcanic material, noting that strong winds were "resuspending ash at Mount St. Helens."

"Strong easterly-southeasterly winds in the vicinity of Mount St. Helens have picked up loose volcanic ash deposited during the 1980 eruptions and are carrying it to the west-northwest," the advisory said.

The agency noted that commercial pilots flying over the region had reported the ash, and warned that, although an eruption was not occurring, the ash itself "should be considered hazardous and could be damaging to aircraft and health." No changes to alerts for the volcano or aviation were needed, though, according to USGS.

Mount St. Helens erupted on May 17, 1980, in a devastating blast that produced the biggest landslide on record and is considered the most economically destructive volcanic event in U.S. history. The eruption killed 57 people and blanketed more than 200 square miles of land in smoke, ash and pumice, affecting places as far as 17 miles away from its summit, scientists say.

According to USGS, the 1980 eruption was the largest at Mount St. Helens in thousands of years, and, while there has not been one since, the volcano continues to cycle through phases of activity and dormancy.

Why ash from catastrophic 1980 Mount St. Helens eruption is swirling around the volcano