(Des Moines) As we near the meteorological winter months, talk around coffee shops, workplaces, and just about everywhere seems to center on one question: what kind of winter can we expect? While it’s impossible to predict winter weather with certainty, we can look back through the historical record to find similar patterns.
State Climatologist Dr. Justin Glisan tells KSOM/KS95 News that we’re entering the meteorological winter months of December, January, and February, under a weak La Niña pattern. This phenomenon is characterized by colder sea surface temperatures in the eastern Pacific and warmer water temperatures in the western Pacific, which can lead to increased thunderstorms out west. These changes in ocean temperatures also affect the jet stream over the United States.
Looking at historical data from weak La Niña cycles dating back to 1950, Glisan notes that these patterns often bring more snowfall to the Upper Midwest, including Iowa. He also points out that, during such cycles, the region tends to experience more frequent cold-weather outbreaks in late January and into February.
Dr. Glisan refers to 2021, the twelfth snowiest on record, 2022 ranked 23rd with the least amount of snow, and 2023 ranked 57th snowiest. He says, looking at this data, if this is a proper La Niña winter, we should experience more snow. However, looking at the 30-year trends, we have actually seen a dip in snowfall amounts across the state.
The snowfall amounts may be slightly harder to predict. Still, Glisan reiterates that more cold-weather outbreaks have been more common in Iowa during weak La Niñas, particularly in January and February.
The National Weather Service is forecasting a 30-percent chance of snow on Friday night, a 40-percent chance of mixed precipitation on Saturday, 50-percent chance of snow on Saturday night, and a 45-percent of snow on Sunday.
