The skies above much of Minnesota were clear Tuesday after several days of haze caused by smoke from Canadian wildfires, but forecasters say the smoke is likely to return later this week.
So thick was the smoke from hundreds of forest fires in Saskatchewan that on Monday a health warning for all of Minnesota was issued – the air quality reading of 187 in the Twin Cities was worse than the levels currently seen in smog-ridden Beijing.
The situation had improved dramatically by Tuesday morning after a northerly wind sent the smoke plume farther south, with the Minnesota Pollution Control Agency saying the state had "good air quality" compared to "unhealthy" just 24 hours earlier.
But some of the smoke is expected to make its way back over Minnesota in the coming days, albeit not at the levels of seriousness seen on Monday. The MPCA is predicting "moderate" air quality between now and the weekend.
The National Weather Service said there will be some high-level smoke and "a milky sky" returning to the region from the west Tuesday afternoon and will be in place by night time.
Paul Huttner, on MPR's Updraft blog, writes: "The massive plume from fires in Alaska and western Canada will still be swirling around the northern tier this week. Expect smoke of varying thickness as winds shift back into the northwest around 10,000 feet.
"Right now, I don’t see a repeat of Monday's incredible AQI reading of 187, but air quality may vary across Minnesota over the next few days."
The MPCA told WCCO that Monday's air quality was the worst seen in Minnesota in the last 20 years, and added that the effect from the Canadian wildfires will remain for at least the next week.
The smoky conditions could possibly last throughout the summer depending on how long the fires burn.
As for the rest of the weather, Minnesota could be headed towards its hottest weekend of the year, with temperatures potentially rising into the 90s on Saturday, but more likely on Sunday.
MPR notes that a "muggy and heated air mass" will be making its way to Minnesota towards the end of the week, and though it's still early, Weather.com is currently predicting a high of 92 in the Twin Cities on Sunday.
Accuweather notes that this muggy weather is likely to bring with it thunderstorms over the weekend.