Climate change is fueling an increase in the intensity and snowfall of winter storms. The atmosphere now holds more moisture, and that in turns drives heavier than normal precipitation, including heavier snowfall in the appropriate conditions.1
Heavy snowfall and snowstorm frequency have increased in many northern parts of the United States.2 The heavier-than-normal snowfalls recently observed in the Midwest and Northeast United States are consistent with climate model projections. In contrast, the South and lower Midwest saw reduced snowstorm frequency during the last century.3 Overall snow cover has decreased in the Northern Hemisphere, due in part to higher temperatures that shorten the time snow spends on the ground.
Snowstorms Shift Northward in the Northern Hemisphere
The regional pattern of fewer snowstorms in the southern United States and more in the North corresponds to a similar northward shift of cold-season storms in the entire Northern Hemisphere over the past 50 years. Mid-latitude storms have decreased in frequency (e.g., in the United States overall) while high-latitude storm activity has increased (e.g., in Canada).4 It is likely that human influence contributed to these changes.5