GRAND RAPIDS, Mich. (WOOD) — There is no question Lake Michigan plays a hugely important role in our weather here in West Michigan.
Filled with a quadrillion gallons of water, the Great Lake affects what we see in the region each day of each year. Let’s break it down by season:
This one is a no-brainer. Lake Michigan is a massive source of moisture during the winter and that means it is a key component in producing lake-effect snow and lake-effect cloud cover.
In fact, Grand Rapids is one of the top 10 cloudiest cities in America because of all the extra clouds the lake throws toward our shore each winter.
There is a seasonal lag in temperatures when it comes to Lake Michigan. Water takes much longer to heat up and much longer to cool down than land. We can easily experience this phenomenon at the beach on a summer day. The sand gets hot fast and the water stays cool, then gradually warms as the season wears on.
This means in the spring, our land is starting to warm up but the water is still icy cold. This causes our lakeshore areas to frequently be a good 10 to 20 degrees colder than inland areas on quiet, sunny, late spring days. It also can set the stage for mirages over the lake as warm air slides over the cold water from Wisconsin, playing with our eyes.
The summer is one of the most beautiful seasons to head to the big lake. It offers a refreshing cool-down for anyone tired of the heat. Its clean waters are typically packed with swimmers and boaters, especially following the Fourth of July.
Lake Michigan is still cooler than the land for most of the summer season. This can often cause the lake to create its own weather. A lake breeze will often form on a quiet day. Lake breezes are shallow circulations that form about halfway through the day. The box current drags cool air onshore from the lake and helps to kick up a band of clouds that run parallel to the lakeshore.
Sometimes lake breezes can produce very strong storms halfway through a summer day that march east as the afternoon wears on. They can even grow to produce severe thunderstorms if conditions are right.
During the fall, the lake is often warmer than the land. This is a huge bonus to farmers. Michigan is home to one of the most diverse crop climates in the world because of Lake Michigan.
At night in the fall when temperatures start dipping below freezing, the lake often will keep our coastal areas mild. This helps prevent hard freezes for many delicious crops in our area, allowing Michigan to be a mass producer.
During the fall, cold air starts rushing in over the water from the northwest. This can often cause the biggest waves of the year and huge erosion concerns on our shore. It also is the most likely time of the year for us to see waterspouts.
What about storms?
Locals will tell you the lake can wreak havoc on storm fronts. Scientists have started digging into this more. One scientific paper claims that it is the upper level wind inside a line of storms that determines if it could survive over the big lake, not the water itself.
One of the largest tornadoes ever to touch down in Michigan — the Hudsonville-Standale tornado — formed right after tracking over Lake Michigan, suggesting that if a storm is strong enough, the lake will not affect it.
There is other research that suggests the friction and lift that wind experiences as it crosses the lake and suddenly hits land can help to increase lift within storms over the land and therefore increase intensity.
There is still a lot of research to be done on this topic. Finding the magic recipe of how the lake affects storms crossing over it is still to be determined.