The skies were clear Wednesday morning, but if you woke up around sunrise and checked the radar, you would have seen some strange images.

The radar from Kansas City was picking up on activity. Even though there wasn’t any precipitation in the area, not even clouds. And what was most interesting was the clusters appeared in concentric circles.

What You Need To Know

  • Certain weather allows the radar to pick up on other objects besides precipitation

  • Birds are migrating south later, thanks to the warm weather this month

  • There are a lot of lakes in and around Lees Summit

What was causing this phenomenon?

How a Doppler radar works

The Doppler radar for Kansas City is in Pleasant Hill, Mo. According to the National Oceanic and Atmospheric Administration (NOAA), the word radar comes from “radio detection and ranging,” and uses radio waves to detect objects.

It is comprised of a transmitter, receiver, display system and antenna. The location of the antenna is atop a tower to get views in all directions with no obstructions.

The antenna sends out pulses of radio waves, traveling at the speed of light. Once an object, such as a water droplet, is hit, the waves will bounce off it and send the energy back to the antenna, where it can then be processed.

The Doppler radar can determine the distance a droplet or target is from the radar and even the velocity of that target. The amount of energy returned or reflected to the radar will produce a reflectivity value, helping meteorologists determine what type of precipitation is falling.

It can even pick up on other objects, including bugs, birds and fireworks.

The Kansas City, Mo. radar captured fireworks set off after the Chiefs won the Super Bowl on Feb. 11, 2024. 

Flocks of birds

On Wednesday morning, the radar pulses encountered objects that were larger than raindrops and snowflakes, and, in this case, it was a flock of birds or several flocks of birds. This can happen if the weather conditions are just right.

Lead Meteorologist Matthew Beitscher from the National Weather Service explains, “The radar is prone to detect these during the night and right before sunrise because an inversion (warm air just above the surface) can refract the radar beam closer to the ground.” This process, he says, “Is called ‘ducting,’ and the stronger the inversion is, the more intense the ducting can be.”

While this can occur at any time of the year, it’s more prevalent during certain seasons. “It can be quite common during the summer when the nocturnal inversion is strong.” The radar is more likely to pick up on bugs on those hot and humid summer mornings.

NWS Meteorologist Ryan Cutter confirmed it was birds taking off that were picked up on the radar on Wednesday morning. Adding, "There are some large lakes in and around Lees Summit."

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