Colder/Snowier Weather on the Way.

Finally, for the past three days or so, models have been extremely consistent with bringing very cold air into the United States in the several days leading up to Christmas.

In fact, BOTH of the most accurate global models show a massive Arctic wave into the United States in the 7-10 day period. What they show is an increasing tendency for long-term Arctic air masses into the region, which will eventually cause the pattern to transition from a stagnant, normal pattern, to a blustery, and very cold wintry pattern. In fact, if the GFS and ECMWF are correct, high temperatures would barely approach the 20's, and might not make it out of the teens by Sunday, December 23. The arctic wave will also feature heavy lake effect snow for areas downwind of Lake Michigan, as well as light snow for areas farther from the lakes.

If this were to happen, it would be a rather abrupt change from the recent pattern, and probably a more welcome pattern. At last! We have signs that this winter will be colder and snowier than 2011-2012!

GFS Forecast for Sunday morning, December 23.

ECMWF forecast for Sunday morning, December 23

Not Much Happening...

 Expect rather "bland" and dull weather conditions for the rest of the week, in advance of a warming trend, which will peak with highs in the lower to middle 40's this weekend, and rain. The storm system that will bringing yet another round of rain will be moving northeast from the Southern Plains, possibly bringing a backside snowstorm for Iowa, Nebraska, and Missouri. It will be quite   interesting to see the eventual track of this storm, but given the fact that models are suggesting that we head into a "split" flow pattern over the next week and a half, its not likely to bring much cold air in its wake. Even with these "bad" winter weather signs appearing, it still looks as if the weather pattern will become much colder, and possibly snowier right around the 21st of December.

As for the longer-range pattern, I have been monitoring the long range models, as well as past historical years, and the pattern looks to be cooperating quite nicely for a harsh, very cold and possibly snowy, January and February. The three main years that I am using are 1957-1958, 1976-1977, 1977-1978, and 2008-2009. 1957-1958 featured a very warm December across the area (with normal precipitation and below normal snowfall), transitioning to very cold weather in the latter half of the winter. 1976-1977 featured EXTREMELY cold conditions from December all the way into early March 1977, with extreme periods of intensely cold weather occurring periodically. Precipitation was below normal and snowfall was near to above normal. 1977-1978 featured a near to slightly below normal December across the area, with very cold weather building into the region for January and February. January 1978 became the snowiest January on record for the region, and February 1978 followed suite with cold and very snowy weather. At this point, the two best matches are 1977-1978, and 1957-1958, which both suggest a snowy, cold end to the winter, likely means that we are heading into a real winter pattern!