Heavier Rain Showers Tuesday Evening Capable of Producing Funnel Clouds

Pat Widolff - Orangeville, IL

Right around 6:40pm Tuesday evening a report came in of a brief funnel cloud east of Orangeville (Stephenson County).  The funnel didn't last long and was quick to retreat back into the clouds.  Pat Widolff captured this picture of the funnel cloud Tuesday evening.

Heavy rain showers quickly developed over northern Stephenson and Jo Daviess counties a little after 6:15pm Tuesday evening.  Severe weather is not expected, but with a surface boundary near the Wisconsin/Illinois border causing an increase in wind shear, some of the heavier rainfall could produce brief funnel clouds.  The same happened in Whiteside County Tuesday afternoon near Sterling/Rock Falls.  A quick funnel, which some reports say actually did touch down, formed before lifting.

An upper level disturbance is moving into northeast Iowa, interacting with the surface boundary and rain showers.  This causes a quick increase in wind shear (spin in the atmosphere) to allow these funnel clouds to form.  The atmosphere is not supportive for severe weather and these funnel clouds rarely touch the ground.