What is the polar vortex? How it can impact snow, freezes in the U.S.
The polar vortex is a large area of circulating cold air above the North Pole. Strong winds keep it contained, but when it weakens, it can wobble and stretch.
- A winter storm is bringing snow, ice, and cold temperatures to much of the U.S. this week.
- Iowa is expected to receive accumulating snow from Saturday afternoon into Sunday morning.
- Northwest and central Iowa could see the heaviest snowfall, with totals of 4 to 7 inches or more.
Winter weather is sweeping across much of the U.S. this week, with multiple systems bringing snow, ice and below-average temperatures from the Northern Rockies to the Mid-Atlantic. The pattern has kept roads slippery and forecasts active, with several waves of cold air and snow moving through the northern and central states.
Iowa is set to see its next round of snow this weekend. Accumulating snow is expected Saturday afternoon, Dec. 6, into Sunday morning, Dec. 7, with the heaviest totals likely across northwest and central Iowa, where 4 to 7 inches — or more in some spots — could fall.
The National Weather Service has issued a winter weather advisory for most of the state. An area in north central Iowa, which is expected to receive the most snow, is under a winter storm warning. Residents are encouraged to monitor forecasts closely and prepare for potentially hazardous travel.
“Snowfall becomes more likely from the Dakotas to Iowa and southern Minnesota by Saturday afternoon into early Sunday as the low pressure system reaches the Midwest states,” Climate Prediction Center wrote.
How much snow will Iowa get? See by region
Rates in the heaviest band could reach an inch per hour, with peak rates occurring from 6 p.m. Saturday to midnight Sunday. Slippery travel conditions may happen. Blowing and drifting snow is possible Sunday night.
Northern Iowa may see a light dusting today, though impacts are expected to be minimal.
Behind the storm, colder air will settle in, with highs Sunday only in the teens and low 20s, and single digits possible in northern counties.
“Accumulating snowfall is likely Saturday afternoon into Sunday morning. The heavier band of 4–7+ inches of snow looks to set up from northwest into central Iowa,” the National Weather Service in Des Moines wrote.
Over the next 72 hours, regional snow totals are expected to be:
- Northwest Iowa (Sioux City area): 2–6 inches
- Central Iowa (Des Moines, Ames): 2–6 inches
- North central Iowa (Fort Dodge, Mason City): 5-7 inches
- Northeast Iowa (Cedar Rapids, Waterloo, Dubuque): 4-6 inches
- Southeast Iowa (Davenport, Iowa City): 3-5 inches
- Southwest Iowa (Council Bluffs, Atlantic): 0-3 inches
Iowa weather watches and warnings
Here are the watches and warnings for the area.
Stay informed. Get weather alerts via text.
Brandi D. Addison covers weather across the United States as the Weather Connect Reporter for the USA TODAY Network. She can be reached at baddison@gannett.com. Find her on Facebook at facebook.com/BrandiAddisonNews.
