A smoky haze over the region prompted the North Dakota Department of Health to urge residents, especially those with respiratory conditions, to limit time outdoors Friday. The alert remains in effect until the skies clear.
Smoke particles can irritate the respiratory system of people with problems such as chronic obstructive pulmonary disease, asthma or allergies, the Health Department said in a news release.
“People reacting to smoke to the extent that it is affecting breathing should seek immediate help from a medical provider,” the press release said.
Smoke problems are likely to continue, according to Daryl Ritchison, interim director of the North Dakota Agricultural Weather Network.
“The fires out west are not going away,” he said. “We’ll see on and off smoke for the next several weeks.”
Upper level wind direction will determine when the skies are smoky with red sunrises and sunsets, according to Bill Abeling, a meteorologist with the National Weather Service in Bismarck.
“It’s the winds in the middle atmosphere, 8,000 to 15,000 feet that are carrying the smoke,” he said. “Right now, winds from the northwest are bringing smoke from northwest Montana and Alberta (Canada) across the region.”
Abeling said the smoke at those altitudes is so dense, pilots are reporting near zero visibility at some points.
The smoke does affect weather on the ground, Ritchison said.
“It cools our temperatures down substantially,” he said. “Saturday could be five degrees cooler than what forecast models would show. It makes it hard to forecast.”
Terry O’Clair, director of the division of air quality for the North Dakota Department of Health, said the new alert is the third in the past three weeks.