‘Overrunning Pattern’ to Bring Heavy Snow to Western Montana

Missoula, MT (KGVO-AM News) - The National Weather Service has issued an alert for heavy snow in the form of a Winter Storm Warning in western Montana that will last through most of the upcoming week, with a possible eight inches of snow on the ground in Missoula.

An Unusual Pattern called 'Overrunning' is in Store for Missoula

KGVO News spoke with Meteorologist Dan Zumpf for details on this unusual pattern he called ‘overrunning’.

“We've had some pretty cool temperatures in place across western Montana over the last couple of days and now some moisture from the Pacific is coming back in from the south and southwest, and it's really riding up over that cold air and wringing all the moisture in the form of snow,” began Zumpf. “It's a real prime pattern that we like to call ‘overrunning’ where the warm air overruns the cold air and it tends to be a very efficient snow producer, so we can be seeing amounts anywhere from three to even over eight inches of snow across western Montana through Monday morning.”

Even More Snow will Continue Through the Week

Zumpf said once Missoula has dug itself out from that initial snowfall, even more could be on the way later in the week.

“Thursday afternoon all the way through the weekend we could be talking about eight more inches total so that's pretty significant for around here to get all these snowstorms so concentrated early on in the winter season,” he said.

Zumpf said the weather pattern will bring moderating temperatures to western Montana.

“The low temperatures in western Montana will stay above zero through the next week,” he said. “We're out of the zero territory around Missoula where the highs will be somewhere in the upper 20s to around 30 degrees for most days.”

Zumpf said this week may be the start of an unusually heavy snow pattern for early December.

The Forecaster said 'We Don't see and End to it, Really'.

“There's more snow on the way,” he said. “More moisture from the Pacific will be coming over so really the only truly dry day that we see here in the next week is probably Wednesday, and even that might still have some snow over the mountains, so we’re looking at a really snowy scenario and we don't see an end to it, really.”

Click here to see a graphic on the snow headed into western Montana, which will bring with it extremely difficult winter driving conditions.