Unpublished

Smoke from California’s wildfires is drifting east across the North American continent, even reaching into the Washington, D.C., area — but the highest concentrations of it is blowing north of Chicago, according to NOAA data and a weather forecaster.

The National Oceanic and Atmospheric Association’s smoke-tracking tool on Friday showed low levels of smoke drifting over the Chicago area. But the air quality index reported by the U.S. Environmental Protection Agency remained at the “moderate” level, meaning that only people unusually sensitive to air pollution should avoid outdoor activity.

It can be difficult for meteorologists to predict where wildfire smoke will blow, said Matt Friedlein, a forecaster at the National Weather Service office in Romeoville. This is because tracking smoke requires monitoring the chemical composition of the jet streams, or high-altitude, fast-flowing winds, overhead.

“It’s tougher to predict, partly because the concentration of smoke will gradually disperse over time, change in heights, [there is] some settling that occurs — that requires different types of modeling to be able to do that,” he said Friday.

Typically, meteorologists can predict the movements of jet streams about a week out, Friedlein said. An analysis of Unisys Weather data shows powerful bands of these winds passing over Chicago in the next three to four days, but Friedlein cautioned that the present amount of smoke created by wildfires would determine the concentration of smoke carried by the winds.

Smoke from wildfires burning in the West was detectable to ordinary Chicagoans as recently as last weekend, Friedlein said. The sky became a milky white, and some people reported smelling smoke in the air.

“Interesting enough about that, that was from [fires] near Ontario, kind of due north of us” — bucking the usual trend of smoke moving along eastward jet streams, Friedlein said. He said that was due to a large, slow-moving weather system that brought the smoke south into the Chicago area.

Sometimes it’s not so easy to tell that smoke is drifting above us, Friedlein said, and knowing it’s there requires advanced satellite tracking and air sampling.

“You can have a lot of smoke up in the atmosphere and not even notice it at ground level,” he said.

An air-quality expert with the Illinois Environmental Protection Agency did not respond to a phone message seeking comment Friday afternoon.

At least eight people have died in wildfires that have engulfed swaths of California over the past month. This year’s toll, in the aftermath of last year’s especially deadly season, which left more than 40 people dead, has reignited the national discussion of climate change as it relates to wildfires.

As temperatures rise across the globe, fresh vegetation proliferates due to early-spring snowmelt, then dries out during summer droughts. This effect is amplified in regions such as California, where fires race upward over rolling hills and are helped along by the Santa Ana or other strong, mountain-terrain winds, said Michael Stambaugh, a wildfire expert at the University of Missouri.

The Midwest is likely to stay safe from wildfire dangers even as temperatures rise over the next several decades, Stambaugh said. This is because heavily agricultural areas such as Illinois are less prone to fires — “our fire environment and our chemistry is quite a bit different.”

“We don’t have a lot of those extremes,” he said.