Bay Area Residents Spot 'UFO Clouds': Here's What They Are

BAY AREA, CA — Several eery clouds that suspiciously resembled flying saucers developed in the Bay Area's skies this week, puzzling residents.

But weather experts assure that these sky oddities were merely clouds, not UFOs. They were "altocumulus standing lenticular" clouds, which appeared in the skies from the North Bay to the western Central Valley as the sun went down on Monday, the National Weather Service tweeted on Monday.

Many Bay Area residents took to Twitter, posting photos of the pancake-like clouds.

What’s up with this UFO cloud up in Berkeley? pic.twitter.com/j6EynYtIpb
— Dwayne (@SuaveLlave) May 25, 2021

Flying saucer clouds in Marin tonight!! pic.twitter.com/xq2qJgYHgI
— Swampyg8trgrl (@maryjolandry) May 25, 2021

These clouds typically form where stable, moist air blow perpendicular to a mountain or a range of mountains. After this happens, large-scale standing waves can form on the mountain's side downwind. If the temperature at the crest of the wave drops enough, moisture in the air can be condensed, forming a lenticular cloud, according to Earthsky.

They also tend to disappear rather quickly so if you see one, snap a photo.

Classic display of Altocumulus Standing Lenticular clouds just inland from the North Bay and over the western Central Valley this evening as the sun set. For more on these types of clouds: https://t.co/fTFHwWCN2j #CAwx #BayAreaWX #lenticularclouds @NWSSacramento @NWSEureka pic.twitter.com/dS6uMwNrU6
— NWS Bay Area (@NWSBayArea) May 25, 2021

“It’s not very uncommon to see,” Anna Schneider, a meteorologist with the National Weather Service, told the San Francisco Chronicle. "The [ACSL] clouds are continuously forming and dissipating around over the mountain. That’s why you get that shape."

@NWSBayArea @MikeNiccoABC7 Thought you would appreciate tonight’s precious view! #lenticularclouds #CaWx pic.twitter.com/eYAJkgwij4
— Roberta Gonzales (@RoGonzalesTV) May 25, 2021

Another sky anomaly was raising hairs in the Bay Area over the weekend when a trail of colorful lights moved across the night sky on Saturday.

Despite recent coverage of UFO sightings in the Golden State, experts say the lights were a lingering effect from a chain of low-flying SpaceX Starlink satellites. The company has been launching more satellites lately as part of an initiative to bring high-speed internet access to people living in rural, hard-to-reach areas, according to the program's website.

SpaceX, led by Elon Musk, launched 52 satellites from Kennedy Space Center in Florida on May 15 and has fired off more than 600 of its 12,000 planned satellites.

READ MORE: Bay Area Residents Report Strange Lights In The Sky Saturday