If you like your holiday season cold and potentially snowy, you may be getting your wish beginning Thanksgiving. As was noted in the Thanksgiving weather forecast post, it appears some colder air will begin moving in to the U.S. around the middle of next week. To the west, temperatures will begin warming up over the weekend and continue through most of next week. The ridge of high pressure responsible for the warmer temperatures is expected to slide eastward and slowly erode through next weekend. Behind the ridge, to the west, very cold air is forecast to move into the central Plains and eventually spill eastward across much of the country.
This change in temperature pattern has appeared rather consistently in previous model runs and it seems the Climate Prediction Center is beginning to believe in the validity of these forecasts. Both their 6-10 and 8-14 day outlooks show colder than normal temperatures across much of the country. The eastern half of the country is expected to experience the below normal temperatures first with much of the country seeing below normal temperatures to begin December.
The CPC’s precipitation outlooks do not call for above normal precipitation in many of these areas. (In fact, they call for below normal precipitation in most locations.) However, if the long-range model solutions verify, temperatures should be cold enough for snow across much of the northern half of the country (the coasts being the possible exception). The Great Lakes especially could see snow in the form of lake effect, which I’m guessing is not something the CPC takes into account in their outlooks given the small area affected by such an event.
Now, we’ve seen these outlooks get flipped on their head in the past, so it’s a little early to start planning for a cold weather outbreak. The models have been fairly consistent in forecasting this cold wave, but the bulk of the cold air is still over a week away from arriving in the lower 48. A lot can happen between now and then, but Thanksgiving is starting to look like a turning point in terms of temperature across a good portion of the U.S.