Melting snow across the Lower Peninsula triggered statewide air quality alerts over the weekend and hazy skies, and similar conditions could return later this spring.
When temperatures warmed, the snow released particulate matter that had accumulated for months into the air all at once, said Michigan Department of Environment, Great Lakes and Energy meteorologist Alec Kownacki.
This winter’s heavy snowfall, warming temperatures, stagnant air, and regular emissions from vehicles all lined up to trigger the alerts, he said.
“It’s all just kind of collecting and accumulating over one spot, over one area,” he said. “So, just kind of worst-case scenario for that circumstance.”
Melting snow could cause poor air quality again later this spring if conditions are right, he said.
“It just kind of depends on the atmospheric setup at that point,” Kownacki said. “If we have warming and then snowpack again and light winds and an inversion, it very well could happen again.”
Pollutants are released into the air when snow melts every spring, but the impact on air quality is not always this intense, he said.
More industrialized parts of the state saw worse air quality, including metro Detroit, Grand Rapids, and Lansing, he said.
Most of the alerts, including those in Mid-Michigan, were for “sensitive groups” such as people with chronic health conditions, older adults, and children. In some places, however, the air quality was poor enough to trigger an alert for the general public.
“It’s very much Detroit, like very downtown Detroit, more so by the population centers,” he said. “And then as you get more into Canada, into Windsor.”
The skies were hazy and foggy in some parts of the state because of the melting snow and mixed-in pollutants, he said.
Kownacki said he expects air quality to improve throughout the week.