December 2014 opened the coldest in 118 years in Chicago, but all the forecasts point to a huge warm-up over the next two weeks:
he scope of the warming being predicted is really something. The global scope of the milder than normal temps is evident from the depiction at the top of this post. The Weather Service’s GFS model, Environment Canada’s GEM ensemble and the European Center’s deterministic and ensemble model are all on board with the onset of a significantly warmer than normal pattern. This doesn’t mean there won’t be some cool days intermingled with the “warmth”. There actually will be. But, these forecasts speak to the overall pattern. Each of these predictions suggest a major pattern about-face heading through mid-December–a radical change from the arctic chill which has dominated the past three months producing the 11th coldest meteorological autumn (i.e. Sept through Nov period) on the books and the 8th coldest November in 143 years of official observations here.
Are prospects for winter cold dead? Don’t count on it. High latitude blocking, a major factor in the cold with which the current season has begun, has been a factor in almost all of our recent winters producing the high amplified (i.e. “buckled” or “wavy”) jet stream patterns which encourage arctic air to dive into the Lower 48.
But not quite yet, it seems. The next week will be seasonable, with temperatures right around freezing. The warm-up, if it occurs, is more than a week away.
On the other hand, I'm in Louisiana tonight, where it's 12°C—too chilly for a long walk in the light sweater I've got on, but a lot warmer than back home. So I'm going to have a look at the Mississippi, then hustle back inside for a pint of something.