Wildfire smoke has invaded Mitchell -- So when is it expected to clear?

Hunter Dunteman, The Daily Republic, Mitchell, S.D.
·2 min read

Jul. 29—It was rather hazy in Mitchell on Thursday as smoke from Canadian wildfires found its way into South Dakota.

This week's National Wildland Fire Situation Report, published by the Department of Natural Resources Canada, reports 263 uncontrolled fires across four Canadian provinces.

The National Weather Service in Sioux Falls said that as the wind shifted to a northeasterly wind overnight Thursday morning, wildfire smoke — mainly from fires in central Manitoba — were pushed across Minnesota and the Dakotas.

"The air is fairly decent in the western part of the state," said Jeff Chapman, a meteorologist for NWS Sioux Falls. "The lowest air quality can be found east of the Missouri River."

The smoke, which reduced visibility to as little as three-quarters of a mile in various parts of the Upper Midwest, prompted the South Dakota Department of Agriculture and Natural Resources to issue an air quality alert for the eastern half of the state.

The United States Air Quality Index publishes air quality ratings for various cities across South Dakota. As of 5 p.m. Thursday, Sioux Falls and Brookings were rated between 175 and 200, in the unhealthy range. Watertown was rated at 411, in the hazardous tier. Mitchell does not have an air quality rating.

Dr. Anthony Hericks, a pulmonologist with Avera in Sioux Falls, said smoky conditions like today can cause airway irritation, even to healthy lungs.

"Those with not so healthy lungs will have that significantly compounded by the humidity," Hericks said. "They'll likely experience a cough, shortness of breath, wheezing, chest tightness and difficulty breathing."

Individuals with underlying health conditions, especially those affecting the lungs and heart, should stay inside if possible, but take precautions if being outdoors is necessary.

"Avoid going out if possible. When it gets bad like this, (some asthmatics) can't leave the house because of their breathing," Hericks said. "If they do. There's another reason for masks this time of year."

Any type of mask or face covering can help filter out smoke, dust and debris particles, and prevent them from entering the airways.

The National Weather Service predicts the heaviest smoke to depart the area by midday Friday. Thursday night's forecasted rain will help.

"The worst conditions will likely be Thursday afternoon into the evening," Chapman said. "There's a chance of rain coming in and that will help clean the air a little bit."

Hericks recommends people use air conditioners to filter the air in their homes as much as possible for the duration of the smokiness.