In areas where there are large commercial wind farms, an interesting - and potentially dangerous - phenomenon occurs: the motion of the turbines creates a "signature" on local doppler radar that looks just like a storm. The large rotating blades affect the flow of wind and on doppler radar, it appears there is a sizeable storm in the area. Below is an image from http://www.wlfi.com/ which is Lafayette's local tv station. You can see the date and time in the upper left corner of the radar image. This was a CLEAR day and the nearest storms were in northwestern Illinois. Where there appear to be a couple hefty storms near Lafayette, there are commercial wind farms.
The question is, can these large wind farms actually interefere with doppler's ability to show rotation in real storm clouds thus endangering the public because of late tornado warnings? If you go to a national radar image, these false storms do not show up; it only happens on the local doppler radar that is used to predict severe storms.