What are the blue dots in the eastern U.S. on last night’s radar?  Birds!

South winds overnight prompted songbirds to move north from Florida to the Great Lakes.  A storm front approaching the Mississippi River and rain from Chicago to Massachusetts brought them to a halt.

Today should a good day to go birding in the areas that have those fuzzy blue dots.  Get out there before it rains.

(screenshot from the National Weather Service full-res radar mosaic)