CHICAGO (WLS) -- Several waterspouts were spotted on Lake Michigan on Sept. 13. Numerous shower and storms developed over the lake and as a result a few waterspouts formed.
ABC7 Meteorologist Larry Mowry said it's not unusual for waterspouts to form this time of year.
There is, in fact, a "waterspout season" for Lake Michigan.
The months of September, October and early November are considered waterspout season as that's when Lake Michigan is is at its warmest. It's also the time of year where we start to see colder air arrive from the north.
That colder fall air over the warm waters of the lake can produce instability, which creates showers. This is similar to the process of how lake effect snow develops, but in this case it is rain.
When winds converge over the lake and with rising air, waterspouts can form. The rising air can rotate and form the waterspout.
Waterspouts can come onshore, but not very often. If one does come on land it usually weakens and dissipates quickly.