This video clip shows 6 hours of nocturnal bird migration (beginning at evening exodus) via NexRad on 4/19 & 4/20 2007 8pm to 2am condensed into several seconds.
Here are the NexRad settings I used:
Product: Regional reflectivity
Background: black (default)
End date: Today
End time: Most recent
Loop duration: 6 hours
To show the entire United States, I clicked "Contiguous U.S." on the map. You can also click on any of the 3 letter NexRad stations for a close-up view. NCAR retains the past 5 days, so in the short term you could select this same block of animated NexRad data by selecting the following settings:
Product: Regional reflectivity
Background: black (default)
End date: Today (or "20 Apr 2007")
End time: 0700 UTC
Loop duration: 6 hours
To upload the video to YouTube, I used screen capture software to record the loop into a 12 megabyte .AVI file.
Sometimes when there is severe weather during heavy bird migration, animating NexRad will often show how the birds are responding by trying to fly around the storm. If I manage observe this phenomena this spring, I’ll capture and post it.
Link: How NexRad detects migrating birds
Link: How to convert UTC