Weather radars capture birds taking to the skies and migrating to warmer climates

Meteorologists and weather enthusiasts alike might notice some noise on radars this weekend even if the air is clear. It’s not weather-related — in fact, the origin is biological.

Weather radars are capturing millions of birds taking to the skies and migrating southward at night. As surface temperatures cool faster than the air above, radar beams are bent closer to the surface, allowing us to detect the birds as they make their way to warmer climates ahead of the forthcoming winter., a website powered by Cornell, Colorado State and UMass Amherst researchers, uses weather radars to estimate biomass flux — in other words how many birds are moving through a given space. At this time of year, between 150 and 200 million may fly over the Lower 48 each night, but during the peak of the migration, half a billion may be flying.

Matthew Cappucci broke down the science during his morning forecast.