Weather Forecast: High pressure starts to break down

Posted at 5:36 AM, Dec 07, 2020
and last updated 2020-12-07 07:36:32-05

MISSOULA — High pressure will be firmly in place again Monday. As we are well aware of by now, those caught under inversions will see highs in the 20s and 30s with dense valley fog and freezing fog possible as well. Those that break free will see sunshine and highs in the upper 30s and 40s.

As high pressure begins to break down Tuesday, temperatures will warm up, however, valleys that have been stuck under inversions (Missoula, Flathead and Mission Valleys) will still have trouble ridding themselves of the cold air. These locations can expect highs in the 30s. Areas that have been able to break free of the inversions will see temperatures range in the low to upper 40s. Once again, dense valley fog will be possible Tuesday morning.

Our first system in quite some time will move in Tuesday night and Wednesday. This is not a strong system, however, light rain, snow, rain/snow or freezing rain will all be possible.

Temperatures will begin to drop to end the week. Expect overall dry conditions Thursday and Friday with highs in the middle 30s Thursday and low 30s Friday.

By the weekend, although models are a bit inconsistent with the timing of each system, a return to a more active weather pattern looks likely. This pattern shift then looks to stick around into next week.