Milwaukee, WI, faced the driest January on record this year, coming in at 3.1 inches compared to the typical 14.9 inches. Outdoor activities such as skiing and ice fishing paid the price.
Professor Ankur Desai with the University of Wisconsin Atmospheric and Oceanic Sciences discussed what could be causing this observed decrease in snowfall.
“This winter we’ve had a weather pattern set up with the jet stream diving south of us for extended periods, keeping us on the colder but drier side,” Desai said. “Part of this is the impact of a phenomenon known as La Niña in the tropical Pacific, and part of this is just the luck of how weather patterns have evolved this winter.”
The La Niña effect is a phenomenon causing weather patterns to shift, occurring every three to five years, according to the National Weather Service. In the winter months of La Niña, cool air tends to loom over the midwest, according to the National Ocean Service.
During this time, trade winds are even stronger as warm air pushes toward Asia and cool air pushes toward the northern U.S. This cool air lacks the moisture content necessary to produce precipitation, meaning that snowfall is not as common during La Niña months in the midwest.
In addition to La Niña, other environmental factors also play a role in accumulated snowfall, Desai said.
“Increasing greenhouse gases from fossil fuel emissions is warming the climate, shortening our overall winter season, with more rain in the shoulder months like December and March,” Desai said. “We have also seen the jet stream shifting further north on average, reducing cold air outbreaks. So warmer and wetter winters are likely to be more common.”
As climate change persists, the concentration of carbon dioxide gas in the atmosphere is exponentially increasing, essentially trapping the sun’s energy in the atmosphere. According to Desai, this causes a shorter winter season, reducing the frequency of potential snowfall.
Climate change has also altered weather patterns across the U.S.
“The weather pattern we’ve had in the past month has promoted cold air outbreaks from the Arctic, but with the jet stream far to the south, those outbreaks have not been able to tap into the moisture [from storms] in the Pacific, Rockies, or Gulf,” Desai said. “As a result, we have the cold but are starved for moisture. We end up unable to support lots of snow.”
UW students can actively participate in reducing their carbon footprint by championing for policymakers to tightly regulate carbon emissions, according to the Center on Budget and Policy Priorities.
Students can also educate themselves on the severity of climate change and make small tweaks to their everyday lifestyle, for example, getting a bike to get around campus or carpooling, according to Carbon Offsets to Alleviate Poverty. Further, UW’s recycling program allows students to reduce food waste.
The interplay of La Niña and climate change is reshaping Wisconsin’s winters, creating drier conditions and less snowfall, which Desai said ultimately impacts both the environment and local outdoor activities.
