Why do we Get So Much Snow?
A major draw for winter enthusiasts to the western Upper Peninsula is the large amount of consistent snowfall. Analyzing snowfall data from the National Weather Service and the Gogebic County Road Commission dating back to 1902, the Ironwood area averages roughly 148 inches of snow per season. The highest annual snowfall occurred during the winter of 1996-1997 when a whopping 298.1 inches fell. The challenging 2023-2024 season saw a total of 66 inches and temperatures that were highly anomalous even when compared to previous El Niño winters.
Big Numbers
A big reason for these lofty totals is the close proximity to Lake Superior and the resulting lake effect snow. As cold north winds flow over the relatively warm waters of the lake, moisture is pushed inland where it cools, condenses, and falls as snow. However, it takes more than a north wind to produce lake effect snow. Several other key ingredients are also needed such as moisture, instability or lift in the atmosphere, temperature spread between the water and atmosphere, and wind direction.
The heaviest snows tend to occur on the backside of moisture-laden low-pressure systems as they move east of the area. Since these spin in a counterclockwise direction, it allows for cold Canadian air to flow over the lake while tapping into the moisture and instability of the low-pressure system. The snow guns get turned off as high pressure eventually builds into the area. Since this air is drier and denser, it prevents the moisture over the lake from rising and producing additional snowfall. This is the reason for the cold “blue bird” days that tend to follow snowstorms.
Lastly, the overall movement pattern of storm systems also plays a major role. During the winter months, the El Niño Southern Oscillation (ENSO) is a primary determining factor for their movement due to its influence on the jet stream. La Niña winters tend to favor storm systems over the Upper Midwest which provides increased opportunities for snowfall. As we saw during the 2023-2024 season, El Niño tends to have the opposite effect with below average snowfall and above average temperatures.
2024-2025 Season Prediction
Thankfully, the 2024-2025 season is forecast to be a weak La Niña pattern. This should provide improved changes for snowfall and more seasonal temperatures. It’s the non-expert opinion of the author that we’ll see around 170 inches of snow and near average temperatures this snow season.
Unfortunately, those hoping for an early start of the season may end up being disappointed. As we are currently experiencing, the fall and early winter phase of La Niña seasons tend to start warm and dry. Based on current long range weather model guidance, this warm and dry pattern may continue until the start of meteorological winter.
The good news is that there will likely be occasional shots of cold air and opportunities for snowfall prior to December. Start doing your best Heikki Lunta dance! If none of these predictions come to fruition, remember this piece was written by a very amateur weather enthusiast trapped in the body of a Physician’s Assistant.
Luke Wyzlic
A native of Ironwood, after working in lower Michigan Luke relocated back to Ironwood in 2013 with his golden retriever, Drake (pictured with Luke), having missed the snow and cross country skiing.
Drake has since passed away; however, Luke will again be expanding his golden retriever family with the addition of Basil and Sage.
Besides his two biggest hobbies, skiing and meteorology, he enjoys trail running and flying.
