Air quality alert through Thursday; elevated forest fire risk for eastern MN

Here we go again.

Tuesday afternoon brought another air quality alert across much of Minnesota. This is set to run until 6am on a Thursday. And there is now a heightened wildfire threat to much of eastern Minnesota, Wisconsin and Michigan.

First our latest air quality advisory for Minnesota.

This presents two different threats to air quality. Northern Minnesota alert favors increased particulate readings from more Canadian wildfire smoke.

The plume of smoke drifting south over the Upper Midwest is clearly visible from space in satellite images from the National Oceanic and Atmospheric Administration Tuesday.

In the south, elevated ozone levels will push air quality index readings higher.

Here are the details on the Minnesota Pollution Control Agency’s latest air quality advisory:

The Minnesota Pollution Control Agency (MPCA) has issued an air quality advisory for northern Minnesota due to smoke from the wildfires, effective from 6:00 pm Tuesday, June 13 through 6:00 am Thursday, June 15. The affected area includes Roseau, International Falls, Ely, Hibbing, Duluth, Two Harbors, Brainerd, Alexandria, Moorhead, Ortonville, and the tribal nations of Grand Portage, Fond du Lac, Leech Lake, Red Lake, and Mille Lacs. The Southeast Minn Ozone Warning is also in effect Wednesday, June 14, from noon to 8:00 p.m. The affected area includes the Twin Cities, Rochester and the tribal nation of Prairie Island.

Smoke from the Canadian wildfires will drift into northern Minnesota, beginning Tuesday evening and reaching Brainerd and Alexandria early Wednesday morning. The smoke will slowly drift south during the day Wednesday and may approach St. Cloud in the evening. Additionally, light smoke may drift into southeastern Minnesota Wednesday evening. The winds will change and push this smoke westward. Smoke will linger over much of the state throughout the day Thursday, but concentrations are expected to ease below the orange category Thursday morning. Additionally, sunny skies, warm temperatures, low humidity and light winds will create an environment where volatile organic compounds (VOCs) and nitrogen oxides (NOx) will react in the air to produce high ozone levels in the afternoon. Ozone will be elevated in the Twin Cities and Rochester during the afternoon hours but will decrease in the evening.

Air quality levels are expected to fall into the Orange Air Quality Index (AQI) category, a level considered unhealthy for sensitive groups, for north and southeastern Minnesota. In the orange zone, sensitive groups should avoid prolonged periods outdoors.

What does this warning mean

Air travels long distances and carries pollutants. During air quality warnings due to fires, the air is mixed with noxious smoke. Smoke from wildfires spreads or persists depending on the size of the fires, wind and weather conditions.

The Air Quality Index (AQI) is color coded. Air quality alerts are issued when the AQI is forecast to reach an unhealthy level, which includes forecasts in the orange, red, purple and brown categories. For a complete description of each air quality category, visit airnow.gov.

Orange air quality: unhealthy for sensitive groups

Sights and Smells: In areas where the air quality is in the orange AQI category due to fires, the sky may appear hazy and residents may smell smoke even when fires are far away.

Health Effects: This air is unhealthy for sensitive groups, and the pollution can aggravate heart and lung disease, as well as cardiovascular and respiratory conditions. Symptoms may include chest pain, shortness of breath, wheezing, cough, and fatigue.

What to do: People in sensitive groups are encouraged to reduce their outdoor physical activities, take more breaks, or engage in less strenuous activity to reduce their exposure. People with asthma should follow their asthma action plan and keep their rescue inhaler close by.

High fire risk for eastern Minnesota

I can’t remember the last time I saw a warning for dry fuels and wildfire behavior covering much of Minnesota.

I have been writing for weeks now about the sudden drought taking hold in Minnesota. A consequence of this rapid onset of drought is that fire feeds grass, marsh vegetation, and trees dry out rapidly.

This means that fires can spread quickly in our area. The Fuel Accumulation Index shows high fuel levels throughout our region.

We used to talk about big fires on 1,000 acres out West. But historically, large and intense wildfires have also occurred in Minnesota. This type of weather pattern is favorable for the rapidly growing and spreading wildfires in eastern Minnesota.

Here’s more of the advisory from the Eastern Area Fire Environment Working Group, Milwaukee, Wisconsin:

Notice on Fuels and Fire Behavior Northeast Minnesota, Wisconsin and Michigan Notice on date takes effect

June 12, 2023

Subject: The Great Lakes states of MN, WI and MI observe significantly elevated wildfire risk with long-term prospects for hotter and drier than normal weather.

Discussion: Since mid-spring 2023, the advisory area has experienced periods of increased fire risk. Last month saw little or no rain, causing vegetation to dry out as the rainfall deficit continues to grow. The area is facing a rainfall deficit of more than 3 inches, and runoff stations monitored by the USGS are reporting levels as low as the 90th percentile.

The long-term forecast describes hot and dry conditions throughout the month of June. In the advisory area, summer fire seasons are typically infrequent and short-lived. However, some of the largest fires occurred in the mid to late summer. For example, the Wilderness Trail Fire (MI-MIS) began on June 3 and spread rapidly exhibiting extreme fire behavior and burning nearly 2,400 acres of jack pine in one burning period.

The main factors were the low needle moisture in the pines, which continue to experience spring decline and may recover more slowly due to the general dry fire environment. Currently, suppressing and sweeping wildfires can take up to five times more energy and effort than usual.

Difference from normal conditions: The fire danger ratings of both the Canadian Forest Fire Danger Rating System (CFFDRS) and the National Fire Danger Rating System (NFDRS) have reached all-time daily highs. Reports of high ignition probabilities, rapid spread, corona fire initiation, and extreme fire behavior. Jack Pine, mixed hardwoods, spruce wormbags, peat moss, and green marsh grass burn easily, which is unusual for this time of year.

Concerns for firefighters and the public:

The entire surface, including the leaves and grass (which appear bright green), is available for burning.

The effect of precipitation is short-lived. Resources must be aware of the long-term impact of drought and expect a rapid increase in wildfire behavior potential soon after any rain event.

Expect increasing ignitions from lightning strikes in forest fuels. Human-caused ignitions from fireworks and equipment are likely as the herbaceous fuels typical of human habitation are cured and receptive.

Intensive monitoring and sweeping will be needed to protect the fireline in lowland grasses where deep fires burn in layers of forest fuels and organic soils. Burning fires can cross cracks in non-mineral soil and rekindle on the other side.

Water from the air (plane or rain) will only slow the forward spread of fires.

Existing buildup, hot dry conditions, and a long amount of summer remaining will bring a very high to extreme risk of large catastrophic wildfires to the advisory area.

Extreme fire behavior, common in record breaking conditions, will occur where fires, fuels and weather elements (i.e. wind) align to create the worst conditions

As smoke from the Canadian wildfires drifts into Minnesota once again this season, a new threat is emerging. The danger of larger wildfires in eastern Minnesota is rapidly increasing as Minnesota’s sudden drought worsens.

Stay tuned.