Canadian rain, shifting winds to boost Minnesota air quality

It’s been a tough week to breathe in Minnesota. This week’s Canadian wildfire smoke front produced the worst air quality event on record for the Twin Cities.

How about some good weather news for a change?

I’m watching rainfall and wind patterns across Canada and Minnesota for the next week. Looking ahead, there is a good chance of significant rainfall in the Canadian wildfire zones that have been producing most of the smoke we’ve seen in Minnesota this year.

A shift in wind direction for the next week over Minnesota should help push the residual smoke aloft over Minnesota today back into Canada through most of next week.

Let’s look at two factors that should improve Minnesota’s air quality.

More favorable wind pattern

Winds aloft and at ground level have been from the north most of this past week. That’s what brought thick smoke into our state.

But winds and the surface and aloft are shifting and will blow more consistently from the south and southwest over the next week.

The National Oceanic and Atmospheric Administration’s Global Forecast System model for the 850 millibar level about 5,000 feet above the ground shows the trend in the chart below. See how those little wind barbs on the loop below stream from the south and southwest across our region through next Thursday?

This pattern will blow what’s left of the smoke plume back into Canada through most of next week. The result will be bluer skies and very little smoke at ground level.

Rain in Canadian wildfire zones

Multiple low-pressure systems will likely produce significant and potentially widespread rain in the hot Canadian wildfire zones in Alberta and Saskatchewan into next week.

NOAA’s Global Forecast System model loop below shows the systems spinning slowly across western Canada between this weekend and next Wednesday.

Several forecast models crank out multi-inch rainfall potential in some of the Canadian fire zone areas next week.

The European Centre for Medium-Range Weather Forecasts model lays out widespread precipitation totals of over 50 millimeters across central Alberta next week with local totals of 150 millimeters. That’s between 2 to more than 5 inches of precipitation!

If these forecasts verify, that could significantly reduce the amount of wildfire activity and smoke in parts of Alberta and potentially Saskatchewan. That’s been the main source region for Minnesota’s smoke so far this year.

Ontario fires are a wildcard

There’s one wildcard in our smoke outlook for the next couple of weeks. Newer wildfires have popped up in Ontario just to the north of Minnesota.

These fires are growing in number and acreage. Relatively little rain if forecast in this area for the next few days. The southwest winds across that region should blow the smoke plumes away from Minnesota through most of next week.

A shift back to northerly winds is possible late next week. If it happens, that could blow more smoke back into Minnesota from a much closer source region.

Stay tuned.