I grew up in Chicago and witnessed a lot of dramatic weather there. During the summer of 2007, the day started out nice and sunny with puffy clouds, then suddenly all of the chimney swifts and swallows left the sky - dropping and blowing down almost like leaves in the Fall. A very strange sight. They took refuge in low lying bushes and shrubs. Less than half an hour later, the sky blackened, and a huge storm roared through that lasted well into the evening hours.
I grew up in Chicago and witnessed a lot of dramatic weather there. During the summer of 2007, the day started out nice and sunny with puffy clouds, then suddenly all of the chimney swifts and swallows left the sky - dropping and blowing down almost like leaves in the Fall. A very strange sight. They took refuge in low lying bushes and shrubs. Less than half an hour later, the sky blackened, and a huge storm roared through that lasted well into the evening hours.