An air quality alert for wildfire smoke has been expanded to cover most of Minnesota — not just the northeast — for the next several days.

The expanded alert now runs through Friday morning. Along with areas where wildfires are burning in northeastern Minnesota, it now also includes Duluth, Moorhead, Brainerd, St. Cloud, the Twin Cities and Winona.

“Very heavy smoke is expected across the Arrowhead today, as large wildfires continue to spread. Hot temperatures, when combined with the air pollution, will exacerbate health impacts,” the Minnesota Pollution Control Agency reported Tuesday.

“A frontal boundary will then spread heavy smoke further south this evening into Wednesday morning as it moves across northern and central Minnesota. The onset of smoke will be rapid. This boundary eventually passes through the Twin Cities and into southeastern Minnesota on Wednesday or Wednesday evening, bringing heavy smoke even further south.”

The MPCA said additional rounds of heavy smoke are possible Thursday into Friday.

Forecasters said fine particle levels in the air may reach the maroon category — meaning hazardous for everyone — closest to the fires, in Lake and Cook counties as well as northern St. Louis County.

“In the maroon area, everyone should avoid any outdoor activity and stay indoors,” the MPCA reported.

Air quality may reach the purple category — meaning very unhealthy for everyone — for the Iron Range, Duluth, and the Interstate 35 corridor between Duluth and Pine City. In those areas, the MPCA said people should “avoid prolonged or heavy exertion and stay indoors.”

The rest of the alert area — including the Twin Cities — may see air quality in the red category, meaning unhealthy for everyone.

“In the red area, sensitive groups should avoid prolonged or heavy exertion and limit time spent outdoors. Everyone should limit prolonged or heavy exertion and time spent outdoors,” the MPCA said.

Collected from Minnesota Public Radio News. View original source here.