Eye-candy view of lake-effect snow shows why Michigan is unlike anywhere in the world

Lake-effect snow has been impacting Michigan for the past few days, and some snow showers are still sticking around in portions of the state. On satellite, the snow has a signature look, though different conditions can cause lake-effect snow showers and clouds to form differently.

In the current satellite loop, the lake-effect snow showers impacting the southwestern and northern portions of Lower Michigan can easily be seen. Bands of snow showers moving to the southeast are currently ongoing and will lead to further accumulations in parts of the state. There’s more to the image than being able to pick out snow showers, as well as some lake-effect clouds that aren’t producing any precipitation.

Satellite imagery of the current lake-effect going on across Michigan. Satellite image by NOAA, via the College of DuPage Weather Lab.NOAA

The movement of the lake-effect bands depends on the wind direction at different levels in the atmosphere. As of right now, winds are coming from the west-northwest just above the surface, driving the lake-effect towards the southeast. If the winds shift, so will the lake-effect.

Besides movement, the wind direction also determines how many bands of lake-effect we will end up seeing, as well as their intensity. The intensity of lake-effect depends, in part, on the size of the “fetch” of the lake. Fetch is the amount of distance wind travels from one shore of the lake to the other. The longer the distance of open water, the larger the fetch.

Currently, the fetch size on Lake Michigan for the lake-effect bands is relatively small. This tends to lead to multiple, smaller bands of lake-effect coming off of the lake like we see today, instead of a few larger bands. Typically, smaller bands tend to have lighter snowfall than larger, singular bands. These smaller lake-effect snow bands can of course still be intense, and drop significant snow.

In the satellite image you can also see the lake-effect bands form over the center of the lake, rather than at the farthest shore, and this has to do with warming. The air moving over the lake needs time to warm up and gather moisture before it can form clouds and later on precipitation. So lake-effect clouds won’t develop as soon as the cold air hits western Lake Michigan. The amount of time it takes to warm the air varies depending on the warmth of the lake, the air temperatures above, and the wind speed.

Besides lake-effect, there are other things going on within the satellite imagery. The snowfall we received over the past couple of days can be seen on the ground in the clear spots on the image. Higher clouds above the lake-effect bands can also be seen moving into the state, moving at a different speed than the lake-effect bands below. This indicates a change of wind speed with height in the atmosphere.

While other states and countries have lake-effect snow, no one has a mitten-shaped state mostly surrounded by water.

All of these weather and land features put together make the place we live have weather unlike anywhere in the world.