Air quality index live updates: Wildfire smoke still brings 'unhealthy' air to many US cities

Smoke from Canadian wildfires that’s been blanketing large portions of the East Coast for days is starting to moderate.

Forecasts show the smoke, which has hung heavy over New York, Chicago, Detroit and Washington, D.C., will ease Friday afternoon and through the weekend. New York City on Friday afternoon held the title of the 2nd-worst air in the world, ahead of Toronto and Montreal and behind Jakarta, Indonesia.

By Saturday, most of the U.S. should drop to yellow or "moderate" air quality on the Air Quality Index, meaning that the air quality is acceptable to everyone but those who are unusually sensitive to air pollution. Detroit and Cleveland will likely remain in the orange or "unhealthy for sensitive groups," according to the forecast.

Thursday, Detroit had the worst air quality in the world, according to AQI rankings and Friday was remained in the red or "unhealthy" category.

There are nearly 500 active wildfires in Canada, and fires there this summer have burned an area about the size of West Virginia. In some areas, authorities discouraged people from exercising outside over concerns the pollution could damage their breathing, especially if they have asthma.

In Washington, D.C., and Chicago, conditions Friday improved, generating a lower risk for most people but reflecting continued concern for people with sensitivities. The worst conditions remained across most of Pennsylvania and eastern New York state, including Buffalo, Syracuse, Rochester and Binghamton, according to EPA predictions.

Air quality forecast to improve as weather pattern changes

The National Weather Service predicts air quality will improve in most areas Friday afternoon and into the weekend as a combination of strong storms moving east across the country and a reduction in Canadian smoke helps clear the air.

"In addition to the heat and the severe storms, Canadian wildfire smoke is expected to continue impacting portions of the northeastern quadrant of the U.S. over the next few days. However, air quality is expected to slowly improve due to a combination of thunderstorm activity and dispersion of the smoke as we head into the weekend," the weather service said in a Friday morning short-term forecast.

Air quality concerns at PGA Tour stop in Detroit

In Detroit, officials at the Rocket Mortgage Classic were monitoring conditions. When the AQI reaches 300 for a sustained period, the PGA tour considers suspending play. As of Friday morning, the AQI was 158 in Detroit, well below that threshold.

Two years ago, PGA officials adopted the policy after smoke from California wildfires made it hard to see balls in flight at the Barracuda Championship near Tahoe.

“It’s not an absolute stop,” Wade Stettner, the tour’s on-site meteorologist, said Thursday. “But it's kind of up to his discretion, more of a recommendation, depending on kind of the situation.”

Summer camps moving indoors as smoke lingers

Summer camps in several states moved many activities indoors as smoke lingered, seeking to protect kids from unhealthy air. Conditions were ranked as red or "unhealthy" in Pennsylvania on Friday morning but were forecast to improve to orange or "unhealthy for sensitive groups" later in the day and then yellow by Saturday.

“There’s certainly a concern, considering that we take children from the cities,” Mark Zides, chairman of the Pennsylvania Camp Association, said Thursday. “Coming up to the mountains for the summer is what summer camp is all about.”

Maggie Groce, one of the directors of the summer camp program at Tanglewood Nature Center in Elmira, New York, said kids were staying inside as the air quality level hit 183 — in the dangerous red zone.

“Ideally, we would love for them to be outside in nature, on the trails, so this has thrown a wrench on our plans,” Groce said.

New York officials issue smoke alert over particulates

The New York State Department of Environmental Conservation extended an air quality health advisory for fine particulates through at least midnight Friday. The alert comes as air quality levels in the Rochester region are expected to remain at the "red" level for fine particulates. The alert covers Monroe, Wayne, Ontario, Livingston, northern Cayuga and Oswego counties.

With the pollution levels elevated, the New York State Department of Health advises people to consider reducing strenuous outdoor physical activities to minimize the risk of adverse health effects.

Will the Canadian wildfire smoke ever end this summer?

Thanks to the ongoing wildfires in Canada, which show no sign of ending, smoky air is likely to be a regular occurrence in the U.S. throughout the rest of the summer, experts said. The Canadian wildfire season usually lasts until October, and the wildfires through June have already set a record for area burned, with the hottest part of the summer yet to come.

"As long as those fires keep burning up there, that’s going to be a problem for us," Weather Prediction Center forecast operations chief Greg Carbin said. "As long as there’s something to burn, there will be smoke we have to deal with."

The unusual jet stream pattern, which continues to periodically funnel the foul, smoke-filled air over U.S. cities, shows no sign of changing or letting up.

"While the fires are ongoing, you can expect to see these periodic bad air days," University of Chicago atmospheric scientist Liz Moyer said. "And the only relief is either when the fires go out or when the weather pattern dies."

What are the Air Quality Index levels?

Governments around the world track and rank their air quality daily, in some cases in realtime, using a color-coded scale of "good" to "hazardous." The AQI measures pollution from wildfire smoke to dust, ozone, pollen and several chemicals, including sulfur dioxide, which comes from burning coal or oil.

The levels are:

• Green/Good: 0 to 50, air quality is satisfactory, and air pollution poses little or no risk.

• Yellow/Moderate: 51 to 100, air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution.

• Orange/Unhealthy for sensitive groups: 101 to 150, members of sensitive groups may experience health effects. The general public is less likely to be affected.

• Red/Unhealthy: 151 to 200, some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects.

• Purple/Very unhealthy: 201 to 300, health alert: The risk of health effects is increased for everyone.

• Maroon/Hazardous: 301 and higher, Health warning of emergency conditions: everyone is more likely to be affected.

Contributing: Carlos Monarrez, Detroit Free Press; Rochester Democrat & Chronicle staff; the Associated Press

This article originally appeared on USA TODAY: Air quality live updates: Smoke brings 'unhealthy' index for many