Wednesday night could very well be the coldest temperature some of us ever experience in our lifetime. That is not an embellishment, but rather a testament to how incredibly cold the night will be.
The coldest temperature ever recorded in the lower 48 United States is -70 degrees Fahrenheit at Rogers Pass on January 20, 1954. While it's likely that record will remain, a few of the coldest locations in Montana could be within shouting distance. Gates Park in the Bob Marshall Wilderness could touch -60. Elk Park on Interstate 15 near Butte could bottom out near there as well. Even out in the Helena valley temperatures could come close to -50, and that's without the wind. most of the state will have lows at -30 or colder.
What's the reason? Arctic high pressure will settle right over western and central Montana on Wednesday night. This high pressure will be extremely strong at about 1064mb or nearly 31.50 inches of mercury.
As much as 12" of new snow will fall through Tuesday night into Wednesday morning. Fresh snow on top of an already deep snowpack will aid in colder temperatures on Wednesday night.
Strong high-pressure overhead at night, with clear skies and fresh snow on the ground maximizes radiational cooling. This is a perfect storm so to speak which will allow for temperatures to drop to levels that some people have never seen before, or may ever see again. Stay warm everyone.