The haze has travelled 1,500 miles from Manitoba, where officials declared a state of emergency last week amid a series of significant fires. More than 25,000 people have had to evacuate the province, and thousands more have had to flee neighboring Alberta and Saskatchewan. As of Monday, crews have struggled to contain the blazes.
The provinces sit above the upper Midwest of the United States, and have caused more significant air quality impacts in neighboring states, like North Dakota, along with small pockets of South Dakota, Minnesota and Montana.
But Dodd said Canadian fires can lift smoke tens of thousands of feet into the air. High winds, like those over the weekend, can spread particles long distances under the right conditions.
He said a lingering trough of low surface pressure over California is making it somewhat hard to predict how conditions could change in the next few days, but they should get clearer, thanks to a deep marine layer and northerly onshore winds.
