If you checked the radar around sunrise this morning, you might have seen a cool phenomenon captured called roost rings. They look like an animation of an expanding donut on a looping radar.
Roost rings appear on radar when the radar beam detects large groups of birds taking flight all at once from their overnight resting spots. This often happens at sunrise when birds take flight to search for their first snack of the day.
The expanding donut-like images on Max Defender 8 are the large group of birds taking flight all at once from a concentrated location and flying higher and further apart- either higher than the radar beam or out of the level of concentration that the radar beam would detect.
Below is another view of this morning’s roost rings using an view called correlation coefficient (CC.) CC shows us how similar in shape and size items are that the radar is picking up on. Raindrops on a CC view have a high CC value because most raindrops in a shower or storm are similar in shape and size. Birds do not have a high CC value because they are less uniform, particularly when they are spreading out and flying away from each other.