The weather radar doesn’t capture most of the creatures’ activity, Morgan said, because they tend to stay close to the ground. The radar focuses on higher elevations.
“What we are seeing is a very small subset of what’s actually happening, grasshopper-wise,” Morgan said.
Unusually wet weather earlier this year has spurred the massive migration of grasshoppers stopping by Nevada’s biggest city on their way north, experts say. The area has seen more rain in six months than the roughly 4.2 inches it typically gets in a year.
The pallid-winged grasshoppers, common in the desert, aren’t dangerous: They don’t bite or carry disease, Nevada state entomologist Jeff Knight told reporters last week. But the insects, which may stay around for several weeks, have fascinated residents and tourists. Photos and videos have captured thick streams of the light-hungry bugs illuminated at night.
While massive grasshopper visitations have occurred before — Knight recalls a handful of similar migrations over the past three decades — Morgan said he hasn’t experienced anything like the latest insect storm in his 16 years living in the area. He has run into nesting hordes that suddenly take flight from bushes and has had a few land on his clothes. But the phenomenon hasn’t bugged him.
“I just brushed them off and let them go about their way,” Morgan said. “And I go about mine.”
Animals that register as storms are not unheard of. Monday morning, the National Weather Service in Blacksburg, Va., tweeted about radar capturing birds’ mass flight at sunrise.
Radars in the D.C.-Baltimore area have picked up clouds of birds, too, and monitoring in Oklahoma once lit up with creatures taking flight minutes before an earthquake. Southern California radars last month detected what seemed to be a ladybug “bloom” 10 miles wide and 15 miles long.
Morgan could not provide the magnitude of the grasshopper swarm showing up on the Weather Service’s radars, explaining that it’s hard to separate the bugs from true weather phenomena at a glance, although the radar has ways of telling them apart. But there’s clearly more than rain at play, he said.
“If we see a sizable mass of something on the radar [and] satellite indicates there are no clouds,” Morgan said, “that’s a pretty big giveaway.”