So much for a cold winter. Despite predictions of a colder, snowier season in the northern U.S. from the National Weather Service’s Climate Prediction Center, the winter of 2016 to 2017 proved anything but.
“It was half right,” National Weather Service Meteorologist Eric Ahasic said of the long-range forecast.“It was colder and snowier than normal in eastern Montana and the Dakotas. Especially in North Dakota, it was a really harsh winter … [but] it was much above normal here in Minnesota.”
The original forecast was based on an anticipated La Niña weather pattern in the Pacific Ocean, which tends to result in cold air from Alaska and Canada being routed through the Midwest. Ahasic said that never really materialized.
“Last winter, 2015-2016, was the strongest El Niño [the opposite of La Niña] we’ve had on record, which only going back to the 1950s,” Ahasic said. “What happened is the La Niña just never really developed. We just hovered in the neutral phase.”
What instead characterized this winter, Ahasic said, was a number of wide swings, from record highs to bone-chilling lows, due to an unusually amplified jet stream that swung back and forth over the region..
“You’d be either way to the north of the jet stream, which meant you’re on the cold side of it, or that jet stream is way off to the north, so you’re on the warm side and way above normal temperatures,” he said.
But the overall trend was still definitely a warm one, particularly in February, which saw a few days top 60 degrees.
“It seemed like we’d have a week of cold weather and then three weeks of above-normal temperatures, so when we average it out, it comes to warmer than average,” Ahasic said.
The precipitation prediction also proved incorrect. Weather service data shows that Owatonna received 38 inches of snow from November to March. That’s more than the previous winter, but well short of 2012 to 2015, some of which saw close to 70 inches of total snowfall.