I realize we’re only 6 days into December, but it’s already been a pretty chilly and snowy start to the winter season… and we have a solid 4 months to go. While the fall and early December weren’t particularly snowy for the metro, much of southern Minnesota has now seen well over a foot of snow… more than double the average to this point. But it’s not just southern Minnesota. More than a dozen major cities well above normal in their snowfall category.
So how do we calculate this? Well, I am using the Accumulated Winter Season Severity Index (AWSSI). This index is based off a points scale. The more points you get, the more extreme your winter is. You get points each day based off the amount of snowfall, snow cover, and specific temperatures. More points the colder and snowier it is. For example, the chart above shows Minneapolis’s current index at 132 through this past Tuesday. That puts the metro in the severe category, or above the 60th percentile when it comes to extreme winters.
But the Twin Cities is only in the severe category, with more than 50 cities in the central and eastern US in the highest category called extreme. Caribou Maine is now having their most extreme start to the winter season on record now with really cold temperatures and have now seen more than 3 feet of snow. Kansas City, St Louis, Chicago, and NYC are also on that list because of the record-breaking snow they saw in November. Even places like Oklahoma City and Little Rock have been extreme… not so much because of snow, but temperatures have been well below freezing more than a dozen times which is unusual this early in the season.
Much of the US is getting a break from the snow this week, but winter-like extremes may push even further south over the weekend with heavy snow possible from west Texas all the way to the Carolinas.