yes i always thought that lake superior had big effect on thunderstorms but i rememeber a few summers ago we had severe storms come from minnestoa and they actually got stronger as they went over the lake temps must have been un the 60's or warm for that ti happen and i also remember a few years back a front comin from the south and we had some pretty bad winds and hail but it came directly from the south how warm would the water have to get for them to actually feed off the lake