For weeks it seems we’ve been locked in a Winter weather pattern and it’s not even Winter. The northern branch of the jet stream has been racing west to east across the northern and central plains. That’s given us our fair share of cold air outbreaks and snow. But the weather pattern appears ready to take a break from its current track.
Next week, as we head toward the official start of Winter on December 21st, warm air aloft from the Pacific Ocean will push the northern branch of the jet stream to near the Canadian border.
The southern branch of the jet stream which has been responsible for lots of wet weather across the southern plains and the Gulf coast will also shift north helping to bring a big warm up to much of the central plains including Kansas City. Average highs next week are around 42 degrees. It’s possible around the 19th or 20th of December that our high temperatures in or very close to Kansas City will be 10 to 15 degrees warmer than average. That means upper 50s and a few of us may even hit 60!
But remember warm spells in December can’t last forever. While we are getting relief from below average temperatures, another dose of cold, dry air will be building over Alaska and Siberia. The temperature contrast will create a strong arctic cold front. Right now, it appears a chunk of this cold air will break free and head for the United States right before Christmas.
The wind flow at about five to seven miles above the earth will help push this Arctic airmass south toward the United States. The jet stream flow will be right out of the Arctic so this will be a bitterly cold air mass for southern Canada and the northern tier of the United States. The coldest of this air may be pushed off into the Great Lakes but at this point it’s possible Kansas City could see well below average highs just in time for Christmas and the start of a new year. Yes, the air would be cold enough to support snow but it’s way too early to know if there will be a storm in the region around the holidays. But we can tell you this, climatologically speaking we have about a 25% chance of having a white Christmas in any given year. Remember, last Christmas Eve when it snowed just over an inch? Could it happen again? Stay tuned!