Early snow causes major disruption in US Midwest

Over 500 flights were cancelled by Saturday, with Chicago’s O’Hare International and Midway International airports the hardest hit, as the first major snowfall of the season hit the US Midwest.

It brought record-setting depths to Sioux Falls, South Dakota, on Friday where over 36cm of snow fell, forcing the morning traffic to crawl and sending dozens of cars sliding off the carriageway.

While it is uncommon for the Midwest to see such heavy snowfall so early in the year, the storm is not unprecedented. Records from the National Weather Service note that 24cm of snow dropped over the area in November 1951.

Related: Winter arrives early on the US west coast

Snow blanketed Oskaloosa city park in southeastern Iowa, with several towns reportedly covered in over a foot of snow. The storm caused several Republican presidential candidates to cancel events in the state, home of the critical first nominating caucus.

Senator Marco Rubio of Florida and Carly Fiorina, a former Hewlett-Packard chief executive, trimmed their schedules, while Senator Ted Cruz of Texas cancelled plans to visit the state.

The southern Wisconsin city of Janesville is also recovering after the storm dumped between 25 and 50cm of snow by Saturday afternoon. In Chicago, Stu Oppenheimer, like many other area residents, was out shovelling snow much earlier in the year than he usually has to.

“Seems like we’re setting records this year,” he said. “I can’t remember an early snow as heavy as this one.”

Thanksgiving woes

The storm centre has since travelled east over the Great Lakes, crossing Michigan and upstate New York, leaving 10-20cm of snow. Forecasters warned that trees that had not yet dropped their leaves could be damaged by the heavy snow.

Now affecting eastern Ontario and Quebec, this storm has left freezing weather and a cold wind. Lake effect snow from the Great Lakes is likely in the next day or two in Michigan, southern Ontario, Pennsylvania and New York State.

Weather forecasting models now suggest the development of a large storm system in the US by Thanksgiving, which is an annual holiday on the fourth Thursday of November.

The storm will move relatively slowly towards the Great Lakes and into southeastern Canada.

The resulting weather is likely to be another spell of snow in the upper Midwest – but heavy rain and thunderstorms across the entire Mississippi Valley – throughout the Thanksgiving weekend.