The unfriendly skies during Thursday night’s atmospheric river storm limited arrivals at the San Francisco and San Jose airports, causing some impromptu detours to Oakland.

According to the National Weather Service, Thursday night’s storm drew wind gusts that reached 53 mph in San Francisco, 63 mph in Contra Costa County, and 79 mph in Los Gatos. That’s not good weather for air travel! So the Federal Aviation Administration (FAA) likely made the right call by invoking the air traffic ground delay program, and as the Chronicle reports, many SFO and San Jose flights were diverted to Oakland or other airports.

“Orders from Federal Aviation Administration towers diverted one corporate jet from San Francisco International Airport to Oakland, while preventing other planes from touching down at San Jose Mineta Airport,” according to the Chronicle. “Alaska Airlines redirected six flights from SFO, sending three to San Jose and three to Oakland.”  

Alaska Airlines, for their part, did offer transportations vouchers to the rerouted passengers. It’s unclear which other airlines saw flights rerouted.

Thursday night’s storms caused a condition called wind shear, which the FAA considers a real problem for airplane safety. “In its many forms, wind shear can change a routine approach into an emergency recovery in a matter of seconds,” the agency says. “An aircraft is affected by the change in wind direction/velocity because the wind also changes the aircraft motion relative to the ground.”

Conditions are milder today, but the SFO Flight Status page shows a fair number of delays and cancellations with flights arriving Friday afternoon and evening.

Related: Floods Force Road Closures Across Bay Area; Ducks Were Swimming On I-580 In Oakland [SFist]

Image: Trinity Moss via Unsplash