Bird Cast is an amazing example of how modern technology can be used to benefit both birders and the birds themselves. During peak migration, there are enough birds in the air at once for them to show up on weather radar! For those of us who like looking at birds, this primarily serves as a heads up that the next day is likely to be good for birding. It is also used to help with conservation in various ways.
If you want to get your own alerts directly, you can subscribe here. Otherwise, the main website is here. Check it out and have a spectacular warbler season!