Although we experienced temperatures well above average for much of December, it has been a brutally cold couple of weeks. Arctic plunge after arctic plunge has pushed their way into the Upper Midwest giving us the coldest readings of the season for more than a week straight. Well that is about to change. The jet stream is set to push further north allowing for a moderating trend over the next couple of days. Follow that up with an air mass change that brings in relatively warm Pacific air, and we have the stage set for a January thaw.
On Monday, the polar jet is still diving into the central U.S. letting arctic air spill into the lower 48. But as a ridge begins to build across much of the nation, this polar jet will retreat north effectively closing the door on this arctic air and allowing temperatures to slowly climb.
You can see that by Wednesday afternoon, much of the U.S. is still quite cold. With the low January sun angle and nearly half the country covered by snow, it takes a while to scour out the cold dense air. But with the help of the subtropical jet stream (the orange arrowed line) and westerly winds across much of the U.S., after a couple of days, temperatures really begin to rise. The mild air surges north into the Upper Midwest, warm conditions develop along the Mexico border, and the frigid cold will stay in Canada… at least for now.
The split in the jet streams with one to our south and another to our north will keep the storm track away from Minnesota for the foreseeable future. While small clippers cannot be ruled out, the potential for any major storm over the next several days remains very low. In fact… if the thaw stays around a while, with no big storms in the future, many parts of Minnesota may lose their snow altogether. Amazing how quickly things can change.