Thick fog across the valley grounded flights at the Missoula International Airport on Sunday, and airport officials said it's possible cancellations could continue into early Monday.
Brian Ellestad, the airport's deputy director, said Sunday evening that while some flights were able to make it out in the morning, by midday incoming and outgoing planes were being diverted to other airports like Kalispell or cancelled entirely.
He said the airport wasn't sure how long it would be until flights could resume, but that visibility conditions had become too unsafe to allow takeoffs and landings.
Leeann Allegretto, a meteorologist with the National Weather Service in Missoula, said that visibility on Sunday had been hovering around the quarter-mile range.
Those conditions, she said, were expected to last into Monday morning and even into the afternoon before they would have a chance to clear up. She said a combination of a cold front and the melting snow on the ground had made for just the right conditions for fog.
"Right now it's very isolated in Missoula, as well as along Interstate 90 near Lookout Pass," she said.
Ellestad said for passengers or people expecting a plane to land in Missoula, the best solution until the conditions improve is to check the airport's website flymissoula.com or get in touch with the specific airline for an update.