SIOUX FALLS, S.D. (KELO) — We’re looking at a snowy end to the week in KELOLAND, particularly on the eastern half of the state.

It may be time to break out the snow blower if you haven’t already, and to find out when and where it will snow, we asked our own personal weather guru, Chief Meteorologist Jay Trobec.

Snow totals and times

The key takeaways? Snow will be moving in from the southwest out of Nebraska, impacting mostly southeastern KELOLAND.

The latest hour-by-hour forecast shows the snow moving into southeast KELOLAND this afternoon and tonight. Keep in mind, this system will start as freezing drizzle for some areas of the southeast and may continue to produce freezing drizzle at times this evening. The storm system is a fast mover and is expected to clear the region by tomorrow morning.

Trobec says the system should move swiftly, with the event being finished as soon as Friday morning.

As for amounts, they will vary. Though Trobac predicts 2-4″ around Sioux Falls based on the latest models, though places like northwest Iowa and southwest Minnesota are likely to get a bit more — possibly as much as 4-6″ near Spencer, IA.

To shovel or snow blow?

“Where are you gonna need the snow blower?” asked Trobec. “Well, where you get the real accumulating snow.”

You may be able to justify breaking out the blower for a few inches in Sioux Falls, but for those near Spencer, it may be best to save yourself the back ache if you’re able and make sure your engine starts tonight.

Behind the scenes in the Storm Center

Trobec let us into his in-studio office to explain a bit of how the forecast comes together, and it’s not quite as much black magic as you may have thought.

“We have a number of different computer models, and they all give us a different solution,” said Trobec. “So we kind of have to choose which one we think is going to be best for the situation.”

He says one of the things they consider in this task is which model has been most accurate in recent days. “When it comes to forecast models, consistency is really the big thing,” Trobec said.

What are these models?

“We lean toward the European forecast model, which statistics say is the most accurate forecast model in the world,” Trobec explained.

Others they’ll check out include the Canadian model, which Trobec says is good when a system is coming out of Canada. There’s also the American model, which he says is especially good for checking long-term trends, and seeing what’s happening in the upper atmosphere.

A snow model on Trobec’s screen

Trobec says that actually forecasting snowfall amounts is one of the most difficult things for a meteorologist to do, because of a variety of elements. “There’s timing, location, and then how much,” he exclaimed. “The how much can be a big difference because — if it’s just a degree or two warmer, we could get rain rather than snow. If it’s a degree or two colder, we could just get snow, and if there’s something in between the different layers of the atmosphere, we could end up with sleet or freezing rain.”

To get the best answer, our meteorologists take data from a number of sources, and cross reference them to get the most accurate reading they can. “That’s why experience is so important,” Trobec said.

You can take advantage of the combined experience of Jay Trobec, Brian Karstens, Meghan Chada, Scot Mundt and Adam Rutt by checking out the KELOLAND Weather page, downloading the Storm Tracker app and staying up to date with the latest weather alerts.