Canadian wildfire smoke returns to Minnesota skies this week

We’ve enjoyed a nice run of trademark Minnesota blue skies the past few days. But another wave of wildfire smoke is blowing into Minnesota from fires in western Canada.

Smoke plumes of varying thickness will blow across Minnesota with the thickest smoke waves favoring Thursday.

Northwest flow

The mid to upper-level wind flow across the Upper Midwest is from the northwest. This blows smoke from Canadian fires in Alberta into Minnesota.

We can expect this pattern to continue to feed waves of mostly elevated smoke into Minnesota through most of this week. The smoke layers will produce a milky white tint to the sky during the day and may produce more vivid reddish sunrises and sunsets this week.

Air quality forecast

The good news for us at ground level is that most of the smoke is aloft so far. That means air quality at ground level where we breathe is good to moderate across Minnesota Tuesday.

Some smoke may reach ground level as the week moves on, so Minnesota Pollution Control Agency meteorologists are monitoring sensors to see if additional air quality alerts may be needed this week.

Here’s Tuesday’s latest forecast discussion from MPCA:

Northwest winds will continue today and light smoke may continue to impact eastern MN. In addition, temperatures will warm into the 80s across much of the state and moderate ozone may become more widespread across southern MN. Much of the state can expect air quality to reach the Yellow category today. Heavier ground-level smoke will begin to move south from fires in Ontario beginning late in the day. This smoke will impact northern Minnesota through tomorrow. Ozone may also become elevated across the Twin Cities tomorrow. The smoke is likely to stick around through the end of the day tomorrow, until a cold front moves through the state from the west. We'll continue to monitor and update the forecasts today and issue an air quality alert if conditions warrant one.

Stay tuned.