Northern Great Plains Blizzards

By Jenna Peneueta-Snyder

North Dakota is the reported blizzard capital of the United States. With global temperatures on the rise, what does this mean for the future of potential blizzards in the Northern Great Plains?

Dr. Aaron Kennedy, CRCS co-lead and Assistant Professor of Atmospheric Sciences at UND, presented, “Identifying Northern Great Plains Blizzards in the Past, Present, and Future,” at the 99th American Meteorological Society Annual Meeting in Phoenix, AZ on January 9, 2019. He addressed how warming climate will impact blizzard conditions in the Northern Great Plains.

Unlike the storms out east, our storms don’t get hashtags, the weather channel doesn’t acknowledge them, but they’re just as important for us,” Kennedy began in his presentation. “There’s a good reason why we get a lot of blizzards, there’s a combination of factors that provide the perfect environment to get blowing snow.”

During his presentation, Kennedy contributes blizzards to the combination of four main factors: topography, land cover, meteorological forcing, and snowpack conditions.

When these factors combine, we end up with not just your stereotypical blizzard, with high snowfall rates and strong winds, but we also end up with these ground blizzards,” Kennedy said during his presentation. “These are situations where the snow has fallen anywhere to several days in advance of the strong winds behind an arctic front and this picks up the snow and this makes our life hectic.”

In addition to these factors, there are various pressure systems that contribute to blizzards in the Northern Great Plains. The first and “most notable” according to Kennedy is the Colorado Lows, a low pressure system with a high level of moisture, strong winds, and reduced visibility. Similar to the Colorado Low is the Alberta Clipper, which has weaker snowfall but strong winds. There also exist hybrid systems and arctic fronts which are responsible for ground blizzards.

Pictured top left: Colorado Low pressure system, top right: Alberta Clipper pressure system, bottom left: hybrid pressure system, bottom right: arctic front pressure system. Photo from Kennedy’s presentation, “Identifying Northern Great Plains Blizzards in the Past, Present, and Future.” Jan 9, 2019.

In order to conduct this research, Kennedy and his graduate students utilize Self-Organizing Maps (SOMs), coupled with North American Regional Reanalysis (NARR) composites, and Community Earth System Model (CESM) to simulate the Earth’s climate system.

From this analysis, the first step was to create a grid of classification using the data gathered by SOMs. Kennedy and his team looked at various patterns and focused on those that presented blizzard conditions. In order to test for blizzard conditions, they used thresholds for wind speed and temperature.

54 class-climatological SOMs created by Kennedy to identify blizzard conditions. The first column shows the SOMS where blizzard conditions are most prevalent. Photo from Kennedy’s presentation, “Identifying Northern Great Plains Blizzards in the Past, Present, and Future.” Jan 9, 2019.

The results showed a reduction of at least one blizzard every two years through the 21st century. Kennedy notes these are preliminary results, so they are a conservative estimate of what might be expected for blizzard conditions in the future. One thing is for certain, a warmer climate will reduce the amount of blowing snow.

For the recorded version of Dr. Kennedy’s presentation, please visit https://ams.confex.com/.