Jet Stream Retreats North

Posted at 5:53 PM, Dec 01, 2020
and last updated 2020-12-01 20:48:26-05

Happy December and happy Meteorological Winter! In the world of meteorology, the winter months are December, January and February. Spring is March, April and May. Summer is June, July and August. Fall is September, October and November. However, the start of "meteorological winter" will be anything but. The jet stream has lifted well north into Canada as a monster ridge of high pressure builds across western North America. This pattern will persist through the rest of the week, this weekend, and into next week. While skies will be clear for most of the state throughout the period, other weather conditions will differ. The valley of western Montana will have inversions which will trap colder air with calm wind conditions. Meanwhile the plains and higher elevations will be breezy with milder temperatures. Overnight lows will also be much colder in the valleys than the plains. Changes are likely toward the end next week. Snow is possible for the second weekend of December.
Have a great day!
Curtis Grevenitz
Chief Meteorologist