ST. LOUIS, Mo. – Well look what was spotted in the skies over southern Illinois! This is not a tornado, although it is related to tornadoes. It was spotted near Carlyle Lake around 10:40 am.
This picture taken by Brandon Lake is what we call a landspout. They are funnels that form along weak wind shifts or pre-existing weather boundaries (sea breeze for instance) or some other atmospheric discontinuity.
That boundary causes a weak spin to develop in the low levels and then when that spin gets pulled under the updraft of a weak shower, like what is seen on radar at the time. That spin gets stretched upward and bingo you get these nifty little spinners.
They rarely touchdown and even if they do they rarely do more than blow over a trashcan, or something similar. Conditions are favorable for additional landspouts this afternoon, especially across central Illinois.