Weather radar signature was military ‘chaff,’ not biblical grasshopper invasion

Radar from the National Weather Service at around 6 p.m. on June 21 initially thought to be a giant swarm of grasshoppers. Photo: National Weather Service, Salt Lake City

Initial reports from the The National Weather Service on Saturday July 7 indicated that its radar caught a swarm of grasshoppers so large it showed up on their radar signatures. The swarm was said to be moving into Northwest Utah.

After further investigation the NWS released and updated statement that “we’ve determined that the most likely cause of the signature on 6/21 was chaff originating from Nellis Air Force Base in Nevada.”

Chaff is a reflective substance sometimes deployed by the military to confuse radars (those that guide missiles, for example) and it can confuse our radars as well. We apologize for the error when we were originally asked about this, as the appearance of insects and chaff can have some similar characteristics, which lead to the error in the original analysis.

While this may have been a false alarm farms in parts of Tooele County, Utah have been inundated with grasshoppers. Rancher Michael Dow told KSL  “Every bit of alfalfa that’s in my fields is gone, I planted a pasture and all the seedlings were about 3/4 of an inch tall Sunday morning, and on Sunday evening, they were gone, it was bare dirt.” Dow went on to say that there are approximately 70 grasshoppers per square yard. They started showing up a couple of weeks ago but the infestation has just become worse.