According to Wade Szilagyi (Waterspout Wade) and the International Centre for Waterspout Research, climatology from 1994 – 2018 shows that waterspouts are most commonly observed on the Great Lakes during the month of September with 544 occurrences. One of the main reasons for this is the lag between air temperature vs. lake temperature where lake effect rain really starts to ramp up in September as the water remains warm (often close to 70 degrees) while the air temperature begins to drop into the 60s. Waterspout ingredients include a mid/upper-level trough/low, warm lake water and low-level convergence. Nathan then gave a little bit of background information on Waterspout Wade; he is a Canadian meteorologist and has done a lot of work studying the formation of waterspouts, he even developed a nomogram that is very widely used when forecasting for waterspouts. The x-axis of the nomogram is Sea – 850 mb temperature difference and the y-axis is the LCL.
Nathan then moved on to share some examples of waterspouts. He showed a Skew-T from Bufkit for Ludington on Monday, September 26th, 2022. It showed ~700 J/kg of CAPE over Lake Michigan with an LCL around 2 kft. This yielded a decent chance for waterspout development. While none were observed on Lake Michigan, there were several observed on Lake Erie near Buffalo, NY and Cleveland, OH. Another example was shared from Monday, September 12th, 2022. Conditions were quite favorable according to Szilagyi’s nomogram and in fact a waterspout was photographed near St. Joseph on that Monday. His final example was from Monday, August 8th, 2008 and in this instance, a waterspout was actually captured on video in South Haven and shared with the Grand Rapids NWS. There is a facebook page for the International Centre for Waterspout Research where Waterspout Wade shares a lot of his maps and graphics and is a great resource to learn more: https://www.facebook.com/InternationalCentreForWaterspoutResearch
You can see the entire presentation in the slides below