Latest update on significant snow event shaping up for the Black Hills

Meteorologist Brant Beckman breaks down the forecast and explains the challenges facing forecasters this weekend.

BLACK HILLS, S.D. – The latest forecast for a significant snow event expected the evening of Saturday, Oct. 6. A WINTER STORM WATCH has been issued between Saturday evening and Monday evening for the Northern, Central, Southern and Wyoming Black Hills for 6 to 10 inches of snow.

Oct. 5, 9 a.m.

As of right now, the trend is snowier and cooler for much of the Hills. Stay tuned, because the forecast WILL change again, and hopefully with more clarity.

Bottom line, as Meteorologist Megan Murat put it, “If you live in the Hills, EXPECT snow. If you live in the foothills, PLAN for snow.”

As promised, new forecast models have come to fruition and offer a great opportunity to discuss the legitimacy of these latest guidelines.

Overall, all models tend to be converging on a “general” consensus that snowfall amounts could be higher than previously forecasted. We knew these forecasts would vary by the hour. Furthermore, there is increased confidence that the general snow event could stretch further into Tuesday morning and even into early Wednesday morning.

However, let’s focus on one snow event at a time. Let’s break down Saturday evening going into Monday evening.

GFS model – Temperature expectations Saturday evening through Tuesday evening

Temperature runs have cooled from our last model run yesterday. Notice how areas around Rapid City seem to dip closer to the 32 degree mark as opposed to 38-40 degrees. As long as the numbers hold, locations like Rapid City are cold enough to sustain more snowfall and less rainfall.

GFS model – Precipitation expectations from Saturday evening thru Tuesday evening

The precipitation expectations showcase that difference. The blue represents snow, while the green and pink colors represent mixed precipitation and general rainfall. The darker the colors, the heavier the precipitation is expected to be.

GFS model – total accumulations expected Saturday evening through Tuesday evening

It is VERY important to understand that models don’t understand the intricacies of the Black Hills as we do. The valleys and towns that we call home are merely numbered sequences represented by boxy, unrealistic visions of what our world looks like.

Having that said, algorithms are swinging wildly from one direction to another. What that tells forecasters and meteorologists is this: the models aren’t handling the situation very well. The last thing anyone should do is take these numbers as fact. Clearly, computer forecasting models can’t decide what’s happening just yet.

As the event gets closer, a better picture will emerge, as current conditions will better help computers make leaps of faith that make better sense.

GOES-16 Satellite – Oct. 6 Friday morning sunrise on the Central Plains


Oct. 4, 5:30 p.m.

The National Weather Service has issued a WINTER STORM WATCH for portions of the Black Hills Saturday night thru Monday night. 6 inches to 10 inches of snow are expected at this time with higher amounts possible.


RAPID CITY, S.D. – A significant snow event for this Saturday evening going into Monday evening looks to be gaining confidence in forecasts.

Accumulations of up to 6 inches of snow in the higher elevations of the Black Hills, as of right now, looks to be the main concern.

Current model solutions suggest higher and lower amounts respectively around the area. There are several different models with several different possible outcomes.

Below are temperatures maps, snowfall maps and wind maps that help tell the story of the approaching system. Over the next couple of days, different model runs will be introduced to this forum, and you can witness firsthand how quickly forecasts can change!

Click the image to run the model

GFS model – snow accumulation amounts from Saturday evening through Tuesday morning

Notice the fine line between the Black Hills and the outlying areas surrounding the Hills. Hardly any snowfall seemingly manages to fall east of the Black Hills through this time period. It is important to understand that with the fluctuation of temperature of only a few degrees, a wind shift or a storm track shift, we can be talking about a completely different scenario.

GFS Model – Temperature changes between Saturday evening and Monday evening

If Rapid City, for example, manages to warm up by 2 degrees Fahrenheit, there’s hardly a chance any snow event is even noticed. The opposite would introduce the possibility of a snow event reaching into Rapid City itself. The chances of all of these conditions remaining the same until this weekend is slim to none. This forecast will change, and meteorologists will have to adapt accordingly to make sure predictions are as accurate as possible.

Blue = Snow Green = Rain Pink = Mixed

GFS model – Shows precipitation moving through the Black Hills area Saturday evening through Monday evening

What we do know is that areas of the Black Hills, particularly higher elevations at this time, stand to receive the most snowfall from this event.

The NewsCenter1 weather team will be monitoring this event closely and will update with any information that changes.

Be sure to download the NewsCenter1 weather app for iPhone and Android!

Categories: Local News