Warm Saturday, then snow returns with an Arctic blast of dangerously cold air

RAPID CITY, S.D. (KEVN) - The weekend will start off warm and sunny with highs in the 50s for many on Saturday. Some spots could flirt with 60°. You will want to get out and take advantage of the nice weather while it is here because significant changes will move in Sunday and into early next week. We are expecting snow and some of the coldest air of the season to move in.

There is growing confidence that rain and snow will move into the area on Sunday. While some spots might see some moisture in the morning, the majority of it will arrive through the afternoon and evening hours. Temperatures will quickly drop and the moisture will switch over to all snow Sunday night. We’re expecting snow to continue Monday, Monday night and Tuesday before tapering off Tuesday evening.

Temperatures are expected to be frigid Sunday night through Tuesday, during the entire duration of this snow event. With such cold air in place, higher snow ratios are to be expected. This means the snow will be light and fluffy for everyone. This type of snow piles up faster than if temperatures were closer to freezing and we had more of a wet snow than dry.

With snow piling up faster than normal, accumulations will likely be higher for much of the area. As of Thursday evening, it does look like you will need to have the shovels ready to remove snow from your driveway or sidewalk. You could probably use a leaf blower to help push away some of the snow due to how fluffy it will be. Chances are looking pretty good that much of the area sees 4″ of snow or more by Tuesday evening. It is still way too early to talk specific numbers, but that’s a good baseline for now.

We say it is too early to talk specifics with accumulations because the storm is still out in the Pacific Ocean. The minimal amount of weather sensors in the ocean makes it difficult to sample the storm and use the data in the weather models to give an accurate number. Typically when we are more than three days out and the storm is still in the Pacific, snowfall totals tend to be inflated and once the storm moves ashore, the numbers come down a little bit.

Here’s a look at the snow coverage expected from this storm. It has been a while since we have seen such widespread snowfall in this area and we desperately need it. Many are still experiencing moderate to severe drought conditions, with extreme drought in parts of northeast Wyoming.

While this storm could drop a decent amount of snow across the area, it will either prevent the drought from expanding, or slightly improve conditions for some, but we will need a few more storms, at least, to make a significant impact to the drought monitor. Here’s to hoping we have an active spring!

Temperatures are going to be dangerously cold early next week. Low temperatures will be well below zero. Many spots will be in the minus teens in the overnight and morning hours, while highs will struggle to even reach zero. There could be some areas that have low temperatures close to -20°. That’s not even factoring in the wind chill!

Winds aren’t expected to be significant during the early portions of the week, but 10 to 25 mph wind speeds will be enough to make temperatures feel like the -20s to -40s. The coldest air will settle in Tuesday and Wednesday morning. Here’s a look at forecast wind chill values for Tuesday night and Wednesday morning, some of the coldest air of this Arctic outbreak.

This forecast is subject to change or update over the next few days, but it is looking pretty certain we have dangerously cold air moving in next week with a good chance at seeing accumulating snow. Stay tuned with KEVN for further updates on our website and on newscasts.