Spring snow storm possible next week

RAPID CITY, S.D. (KOTA) - There are posts circulating social media about a big snowstorm possible near the early to middle of next week. Is it true? Yes, we are monitoring a potential setup that would bring some heavy snow to the central & northern plains. The posts on social media have snowfall maps without much context to them. Just a bunch of big numbers that could cause panic. As a meteorologist, I felt the need to try and address this quickly. Could we see a lot of snow? Sure, but it is highly unlikely we see anything close to the numbers being floated across the internet. I’ll explain my thinking below.

Take a few minutes to look over the graphic above. I took some time today to dig and find out what the biggest snowstorms were in downtown Rapid City history. Some of the weather maps posted are calling for more than two feet of snow next week. That’s not happening. The biggest storm we have seen was back in 1927, where 25.6″ of snow fell over a three day span. All of the other storms were under two feet. There have only been SEVEN storms in the city’s history to produce more than 20″ of snow over the entire duration of a storm. Historical data dates all the way back to 1888 - yes, the 1800s. So, very very few storms have even come close to two feet of snow.

Something to take note of - five of the six largest snow storms to hit Rapid City have been in the month of April. While we have our minds set on sunshine and warmer weather as we march our way through Spring, it isn’t uncommon to see big storms in April. After all, it is our second snowiest month on average.

The spring storms typically provide much needed moisture across the area, and this year is no exception. We are well below normal in moisture and snowfall since July 1. Compared to average, we are more than a foot below normal for snowfall and almost two and a half inches below were we should be in terms of moisture. The area is being impacted by drought conditions. Severe to extreme drought covers much of western South Dakota and northeast Wyoming. A big storm will help for the short term and stall the drought conditions from worsening, but we would need a few solid storms to make a big impact for the long term.

Here’s what the models look like for the area next week. They’re calling for a large storm system to eject from the Rockies and sweep across the plains, bringing an active weather pattern for many. While this blog focuses on the snow potential here in the northern plains, those in the southern plains could face a big time severe outbreak.

There has been a little wobble recently in the storm track. It shows the storm hitting KOTA Territory or shifting a little north/south. This isn’t anything new when it comes to forecasting a storm this far out. The amount of weather instruments in the Pacific are slim to none, so the models do not have actual data to base the forecast off of. This is why when a storm is 4-7 days, or more, away from impacting the area, the snow totals seem to be astronomical. Once we get to about 2-3 days to the storm, models tend to come back to reality because there is a better sampling of the amount of moisture with the storm, where the storm is located to get a better idea on the path of the storm, and more.

We’re also keeping a very close eye on the amount of wind with this storm. As of now it looks like there could be more significant wind to impact the area at the same time as this storm, which would cause blowing and drifting snow, whiteout conditions, and make driving extremely difficult to nearly impossible in areas.

While the confidence in storm track and snow totals are low, the consistency has been in the models for timing purposes. Models are showing Tuesday and Wednesday as the primary days for when this storm is expected to hit. There still could be a shift in timing for the storm, but early to middle next week seems to be a good bet.

Let’s take this one step at a time. Right now we are in the “aware” stage. It is time to be aware that we have a potential spring snowstorm on the way next week. If consistency remains by the weekend, then we can start to talk numbers and prepare for a storm to hit. This will be the main focus of our weather talk going into the weekend and into next week. Stay tuned to our website and social media page and be sure to watch GMKT, KOTA Territory News at noon, 5:30 & 10 p.m. for the latest updates.