When this takes place, the wind flow is out of the northeast bringing in very cool air from off Lake Michigan. Lake Michigan, similar to other large bodies of water, takes a long time to heat and cool. As a result, after a long, cold winter, its water temperature is in the 30s. Since this is often cooler than the daytime air temperature over the land during the spring months, the lake can produce very chilly weather for much of eastern Wisconsin. Whenever the large scale wind flow becomes weak, Lake Michigan can actually create its own wind.
Local winds take place all over the world.
Some take place near mountains, while others take place near the oceans. Milwaukee's own local wind is caused by the temperature differences between the air over Lake Michigan and the air over the land. Whenever the large scale weather systems are fairly weak, a cold Lake Michigan can create its own wind. This local wind is due to a wind circulation known as the lake breeze. It is caused by the differences in pressure between the air just over the lake and the air over the land.