Why were those storms so windy?
Storms that are in a bowing line, as shown above, are called bow echoes. However, in more intense wind events, such as today's storms, the name becomes a derecho (der-AY-cho), also known as a long-lived wind event. While these storms may not have been sustained as powerfully as they were at the beginning, it is still considered a derecho, and can be called either a derecho or bow echo.
With all the wind, is it possible that there was a tornado?
During the entire storm, The Weather Centre team was watching velocities - or a special radar type that determines tornadoes by wind direction- , and we never saw a defined rotation in these storms. Another telltale sign of a tornado would be the broken branches spread in almost a circular direction. However during our damage survey, we did not find that at all. Our damage survey was conducted in one of the harder hit areas.
How strong did the winds get?
At Midway International Airport, winds officially reached 75 miles an hour- equivalent to the bare minimum strength of a Category 1 hurricane. So you can say that you were in a hurricane if you lived near Midway!