"Rain Cloud" On Weather Radar Turns Out To Be A Ladybug Swarm


A swarm of ladybugs was spotted by the National Weather Service Radar on June 4, 2019 (Credit: NWS/Twitter)

At about 9:00 p.m. on June 4th, 2019, Joe Dandrea, a meteorologist working the late shift at the National Weather Service (NWS) station just north of San Diego, CA, noticed what appeared to be a large rain cloud on the radar. However, upon peering closer, he realized the "cloud" comprised a huge mass of tiny, flying dots.

Curious to find out what had just crossed his screen, Dandrea contacted a weather spotter near Wrightwood, CA in the San Bernardino Mountains, where the massive blob appeared to be. Part of the NWS's SKYWARN volunteer program, spotters are trained to keep their communities safe by informing the agency of any local weather hazards, particularly severe storms. Dandrea's suspicions proved right. The "rain cloud" was a swarm of ladybirds flying in synch.

The ladybug bloom may have been caused by migrating convergent lady beetles (Credit: ifas.ufl.edu )

Though the bloom appeared to be a massive 80 miles by 80 miles on the radar, Dandrea believes the lady beetles were not flying in a concentrated mass that big. He suspects the ladybugs were spread throughout the sky, flying at altitudes of between 5,000 and 9,000 feet, with the most concentrated mass measuring just 10 miles wide. “I don’t think they’re dense like a cloud,” Dandrea told the Los Angeles Times. “The observer there said you could see little specks flying by.”

Given the distance, it was hard to determine what ladybird species was responsible for the phenomenon. One possibility is the adult convergent lady beetles that migrate from the Sierra Nevada mountains to Los Angeles County's San Fernando Valley every spring in search of aphids and to lay eggs. In early summer, once the food source declines, the hungry beetles leave in droves to higher elevations.

Adult convergent lady beetles migrate to the San Fernando Valley in spring to lay eggs and eat aphids (Credit: calag.unacr.edu)

This is not the first time the powerful NWS radars have picked up non-weather targets. Past "angels," as the agency calls them, include migrating birds, road traffic, and even sunrises and sunsets, which according to the National Oceanic and Atmospheric Administration, "Show up on National Weather Service radar screens as a spike in the direction of the sun."

Resources: latimes.com, ABCnews.com

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  • agent8
    agent8Monday, September 16, 2019 at 5:50 pm
    weather radars be like: omg rain cloud. me: TwT
    • iThursday, September 12, 2019 at 10:57 am
      so fun
      • emilTuesday, September 10, 2019 at 1:55 pm
        I live in California
        • yp5
          yp5Thursday, September 19, 2019 at 12:24 pm
          so funny
          • yp5
            yp5Thursday, September 19, 2019 at 12:17 pm
            so funny
          • heyTuesday, September 10, 2019 at 1:53 pm
            • princeslps
              princeslpsTuesday, September 10, 2019 at 1:52 pm
              • agent8
                agent8Monday, September 16, 2019 at 5:50 pm
                haha very funny ;)
              • blahTuesday, September 10, 2019 at 1:48 pm
                never heard of that before
                • emilTuesday, September 10, 2019 at 1:48 pm
                  so coooool and pretty
                  • emilTuesday, September 10, 2019 at 1:40 pm
                    how big is that swarm?
                    • Turtle loverMonday, September 9, 2019 at 10:57 am
                      • 2006girl
                        2006girlThursday, September 5, 2019 at 7:45 pm
                        Just wow! That’s so cool (๑˃̵ᴗ˂̵)