Wildfire Smoke Hovers Over U.S. for 3rd Day, Pushing South and West

Hundreds of fires raging across eastern Canada continued to spread clouds of dangerous pollution across much of the eastern United States on Thursday. Officials issued warnings about air quality in a broad swath of the country, from New York west to Indiana and as far south as the Carolinas.

Major cities including Philadelphia, Washington and New York woke up to unhealthy levels of air pollution, one day after New York City registered its worst air quality readings in decades. Although conditions in parts of the Northeast on Thursday were expected to be better than the day before, the noxious air was spreading across a growing part of the country.

The source of the smoke is an outbreak of blazes in Canada, which have forced tens of thousands of people from their homes. About 250 wildfires burned out of control in the eastern part of the country as of early Thursday, authorities said, about 150 of them in Quebec. Some have been burning for weeks.

Officials in states and provinces on both sides of the border warned of the threat of the smoke, which has forced some people to don masks in a grim reminder of the pandemic conditions of recent years. The smoky haze closed the National Zoo, disrupted flights and forced sudden changes of plans.

On the steps of the Lincoln Memorial in Washington, teenage girls whose commencement ceremony had to be called off took pictures in graduation regalia, although the smoke was too thick to make out the Washington Monument halfway down the National Mall. One of the graduates, Carly Svec, 18, said the ceremony was postponed just 15 minutes before it was supposed to begin.

The smoke that choked New York on Wednesday was expected to push southward Thursday and move west, into the Ohio River Valley, on Friday, the National Weather Service said in a forecast. It was expected to appear as a widespread haze that could dip as far south as Florida, and not the dense mass of smoke that covered New York on Wednesday.

A storm system swirling off the coast of Nova Scotia in recent days blew smoke from the fires south into the United States. Forecast models for Thursday showed that thick smoke could return to New York later in the day if sea breezes pushed smoke currently hovering off the coast back inland.

The effects of the fires are expected to be noticeable even on the other side of the Atlantic Ocean. Scientists at the Climate and Environmental Research Institute in Norway who are tracking the smoke through the atmosphere said it has moved over Greenland and Iceland since June 1, and observations in southern Norway have confirmed increasing concentrations of aerosols.

This article originally appeared in <a href="https://www.nytimes.com/live/2023/06/08/us/canada-wildfires-air-quality-smoke/heres-the-latest-on-the-worsening-air-quality-in-the-us">The New York Times</a>.