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Environment | Land

Does Global Warming Mean More Winter Snow Storms?

While Northwest residents confront a winter snow blast, new research is pointing to climate change as a possible reason that harsh Arctic weather is pushing into some lower latitudes.

The new study, published by Atmospheric and Environmental Research, is contradicting what current climate models tell us about winter weather patterns. It suggests warming trends in the spring, summer and fall are causing colder winters with more severe storms. The study’s lead author, Judah Cohen, says winter temperatures should be warming the most, according to climate models. But actual temperatures aren’t lining up with what those models have predicted.

“The one season where the models did not do as well is winter,” he says. “I mean, they did not do well at all. They predicted the continued warming trend, and actually – [in] the observations – there is no warming trend.”

Cohen says when warmer summers melt Arctic ice, early snowfall in northern Europe causes polar winds - called Arctic oscillation - to more easily blow south in the winter. That means colder temperatures and record snowfall. Historically Arctic oscillation keeps winds blowing east to west, thus causing warmer winter temperatures in the northern hemisphere.

Snow in Portland 2012
Snow falling in southwest Portland

He says this winter weather pattern is emerging in the Northwest, but it is not as pronounced as it is in other regions. Areas that will feel the most effects include the eastern United States, southern Canada and northern Eurasia. Cohen says the Pacific Northwest’s recent snowfall could be a result of changing Arctic oscillation.

This research could help fill in a few gaps in the complexity of current climate models, he says.

“This mechanism that we show in the paper is really absent, or deficient, in the climate models that are being used for these assessments, or predictions, of what’s going to happen in the coming decades,” Cohen says.

He says a team of researchers is also working with climate modelers to help improve long-range forecasting.

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