Temperatures will remain mild and dry for most of this week, but strong and gusty winds will blow over the plains at times, particularly along the Rocky Mountain Front and neighboring places.
As a result of severe temperature inversions over the valleys, the valleys in Southwest and Central Montana will stay much colder than the surrounding plains.
Temperatures in the valleys of Southwest and Central Montana, as well as winds, especially strong gusts, are the primary expected concerns through Wednesday night.
Longwave moving east from the Pacific Northwest/British Columbia will flatten out an upper-level ridge with an axis running up through the Northern Rockies and shifting east into Montana through this evening.
As westerly flow above ridgetops peaks at 50-65kts several times throughout the period, an extended period of strong winds is expected along the Rocky Mountain Front beginning this afternoon and continuing through Wednesday, with a strong pressure gradient in place across the Rockies and lee-side troughing to the east.
Mountain wave enhancement is also projected to be aided by favorable vertical temperature and wind profiles, especially on Tuesday, when the greatest winds are forecast.
Surface temperatures have been substantially below the deterministic and probabilistic guidance for today, as has been the case in the past when cold pools have formed in the valleys of Southwest and Central Montana throughout the winter.
The cooler temperatures are expected to persist through Wednesday as a result of limited mixing beneath the temperature inversion, which is expected to persist through Wednesday.
Forecast high temperatures for Tuesday and Wednesday are based on a combination of the coldest available guidance and the previous day's high temperatures; however, these forecast high temperatures may still be too warm because even the coldest available guidance attempts to raise temperatures more quickly than experience would suggest.
The rest of Central and Northern Montana will see temperatures that are far above average during this period, particularly in downslope locations along the Rocky Mountain Front and in the Central Montana Rockies.