Here in Western Wisconsin, we saw our biggest snowfall of the season so far yesterday. A whopping 9” fell in Eau Claire Monday night into Tuesday. All of that snow came from a low pressure system known as an “Alberta Clipper”. An Alberta clipper is basically just an area of low pressure that originates in the Alberta province of Canada. We see these a bunch of times throughout the winter months. Typically, these clippers are normally quick moving and don’t tend to drop a lot of snow. However....
Yesterday, we did not see your average clipper. It threw the forecast models and us forecasters quite the curve ball. A large swath of 6-10” was dropped across the heart of the Chippewa Valley. Below is a look at snowfall totals across the area.
The storm created a mess out on the roadways. There were hundreds of accidents reported and one of them, a 10 semi-truck crash, caused a major pile up and shut down westbound I-94 for a time on Tuesday. Winds picking up Tuesday afternoon helped to lower visibilities and cause blowing and drifting snow. Wind gusts out of the northwest were between 20 to 40 mph. A viewer sent us this photo of a school bus that spun out in Elk Mound on Tuesday afternoon. Many schools either delayed start or let out early that day. Many afternoon classes and activities were canceled, including sporting events. The roads were horrible and Wisconsin DOT even labeled a decent stretch of Highway 53 and I-94 as “travel not advised.”
So what caused an Alberta clipper to become a “mutant clipper” (as Darren affectionally calls it) and dump this much snow and cause these many headaches? Well there’s a few reasons. First, the low pressure system had a good amount of moisture to work with. A bigger factor was the strong upper level energy that not only deepened and strengthened the low, but it also slowed the whole system down. We could kind of tell this was going to be a fun one because the forecast models were consistently changing and didn't really come to a solid agreement until later Monday evening.
Take a look at the radar replay that the National Weather Service in La Crosse put together. It starts at 6 pm on January 13th and runs through 1 pm on January 14th. Notice there is that initial heavy band of snow, and then as the area of low pressure strengthens, a heavy snow band sets up and pivots right over the I-94 area. That’s why we saw such high totals in the Eau Claire area.