Did a massive swarm of grasshoppers disrupt weather radar? What we know

A weather radar outage in June had Utahns fearing that a swarm of grasshoppers of biblical proportions was headed toward Tooele, Utah.

a June 21 image The weather radar showed a huge blue blip heading toward Utah City. Some people wondered if it was a swarm of grasshoppers so big that it hit the radar. Utah has battled grasshopper swarms in the past, and the pests are particularly bad during dry seasons, like in 2021. That year, the grasshoppers swarmed in frighteningly impressive numbers and destroyed crops, according to a report. Deseret News report.

However, the June rumors turned out to be inaccurate. The National Weather Service (NWS) office in Salt Lake City made a mistake when previously asked about the radar signal, and on Saturday apologized for the mistake and explained the reason for the radar outage. .

“There’s news about a swarm of grasshoppers that could show up on our northern UT weather radar,” NWS Salt Lake City tweeted on Saturday. “After further investigation, we determined that the most likely cause of the signature on June 21 was straw originating from Nellis Air Force Base in Nevada.”

NWS Salt Lake City went on to explain that the straw is a reflective substance deployed by the military to confuse radar. Chaff is usually deployed to confuse radars in military instances, such as disrupting missile guidance radars, but can also confuse weather radars.

“We apologize for the error when originally asked about this, as the appearance of insects and thatch may have some similar characteristics, leading to the error in the original analysis,” NWS Salt Lake City tweeted.

The NWS did not rule out a swarm of insects when the first radar blip occurred, but later apologized and said further investigation showed that it was chaff instead. The NWS also said it was unable to remove radar images showing the blue cloud moving across radar because it provided it to news outlets who later shared the story.

David Church, a science and operations officer at NWS Salt Lake City, said news week that although chaff is a relatively common radar occurrence, this time the signature was more spread out and resembled a swarm of insects.

The insects are rarely so concentrated that they show up on NWS Salt Lake City radar, Church said, but the radar typically picks up migratory birds.

news week reached out to the Utah Department of Agriculture’s Pest and Insect Program by email for comment.

The idea that the radar outage could be due to grasshoppers isn’t entirely unfounded, as Utah and other western states have battled grasshopper swarms in the past. Drought usually increases the likelihood of swarms as the insects thrive in dry conditions.

However, dry conditions have eased across much of the West after a particularly wet winter along the West Coast. There was also above-average snowfall in the western mountain ranges, supplementing the area’s waterways all summer as the snowpack melted.

The US Drought Monitor map shows that Utah is out of the worst of the drought. More than half of Utah is drought free. At this time last year, no part of the state was free of drought.

Grasshoppers continue to pose a problem for Utah farmers. They may not have disrupted the NWS radar, but swarms of grasshoppers destroyed crop fields around the same time the radar picked up the chaff.

“All the alfalfa in my fields is gone,” rancher Michael Dow told KSL television in Salt Lake City. “I planted a grass and all the seedlings were about three-quarters of an inch tall on Sunday morning, and by Sunday night, they were gone, it was bare ground.”