Lobes of the Polar Vortex Hit the United States

Posted at 6:34 PM, Jan 28, 2019
and last updated 2019-01-28 20:37:13-05

The coldest airmass in years is diving through the north-central United States, with Montana receiving just a glancing blow.  This air is coming straight down from the North Pole but will only briefly clip areas of Montana near the Dakota border.  Even colder air (temperatures down to -45) will hit the eastern Dakotas and Minnesota over the next few nights.  A WIND CHILL ADVISORY has been issued for eastern Montana into Tuesday morning for wind chill values that could come close to -40.  In those conditions, frostbite could develop in as little as 10 minutes on exposed skin.  While that dangerous cold wind chill value will be found only in eastern Montana, the entire state will start Tuesday off with a very cold morning.  Many towns will be in the 0s and low 10s, but some sheltered mountain valley locales in western and central Montana will be down near -10.  Bundle up!  Tuesday will be another mostly sunny, bluebird day with highs in the 20s for most.  Eastern Montana will have highs closer to 0.  Wednesday, some warmer air will move in with clouds and a few isolated snow showers.  Temperatures across Montana’s prairies will start rising through the 30s to around 40.  Valley locations will develop inversions trapping colder air for most of the week.  By Thursday and Friday, Montana’s prairies will warm into the 40s to near 50.  That warmth will come with stronger wind gusting higher than 30mph.  This weekend a new storm will move toward the state on Saturday.  Right now, snow should hold off until late on Saturday.  However, snow will be widespread and fairly heavy on Sunday.  Travel through most of Montana and our neighboring states will be difficult in the snow and reduced visibility.  Stay tuned for updates and snow accumulation forecast as we get closer to the weekend.

Stay warm.

Curtis Grevenitz