Even though the winter season most of us are familiar with, “astronomical” winter, doesn’t begin until the winter solstice on Dec. 21, we meteorologists have already started our winter season. Meteorological winter began Dec. 1 and runs through the last day of February.
It looks like Mother Nature is following the meteorologists’ calendar this year as bitterly cold arctic air plunges southward across much of the West and eventually expands across the Plains and Midwest. This will send temperatures to their lowest levels of the season – and in some cases, potentially the coldest in several years.
Here is the general timing for the arrival of the main arctic cold front, by region:
Monday: Northwest, northern Great Basin, Montana
Tuesday: California, rest of Great Basin, Wyoming
Wednesday: Desert Southwest, northern and central Plains, Colorado, New Mexico
Thursday-Friday: Upper Midwest, mid-Mississippi Valley, parts of Southern Plain