Flights at SLO Airport have been diverted, delayed or canceled — because of nightly fog

The San Luis Obispo County Regional Airport has experienced flight delays and cancellations over the past two days — all because of fog.

“We’ve had very low fog coming in at nighttime that impacts aircraft ability to come into the airport,” Craig Piper, the airport’s assistant director, told The Tribune.

Additionally, the airport’s instrument landing system is currently being replaced by the Federal Aviation Administration, which may have played a part in the delays, Piper said. The system is expected to be up and running again by the end of next week.

But even if the landing system was functioning, pilots have to be able to see the airport’s runway at a specific distance and altitude in order to land, Piper said.

“If they can’t see the runway, they have to abort,” Piper said. “They divert to another airport or go back to where they came from.”

According to the airport’s arrival schedule, flights that were scheduled to arrive Wednesday night all showed some type of delay or cancellation. Most flights set to depart from the airport early Thursday morning were also showing either a delay or cancellation through about 8 a.m.

Piper said the airport had a similar issue with fog from Tuesday night through Wednesday morning.

On both Tuesday and Wednesday nights, none of the planes scheduled to land and remain overnight at the airport before a morning flight were able to land, according to Piper.

Piper said the airport does see widespread weather-related delays and cancellations at least a few times a year, but it varies. They generally see fog-related delays in June, and experiencing them in November is unusual.

“My understanding is the fog came in pretty early and pretty thick and pretty low, and that had an impact on our flights coming in,” Piper said.

PG&E meteorologist John Lindsey said San Luis Obispo County is in the midst of a “tranquil” weather pattern that’s expected to last until Friday.

“We’re seeing gentle winds and a weak pressure gradient, there’s nothing to mix out or blow out the fog and mist,” Lindsey said Thursday afternoon. “The dense fog and low marine layer will be common through tomorrow.”

The weather should change by the weekend, with northeasterly winds in the morning producing clear skies and warm temperatures, and northwesterly winds in the afternoon, Lindsey said.

But next week looks like a similar weather pattern, with fog, low clouds and even gentler offshore winds forecast to start on Monday and continue through next Thursday or Friday, Lindsey said.

“It could be more problematic than it was the last couple of days,” Lindsey said.

Lindsey added that he has seen weather patterns like this before at this time of year, and it generally happens right before a period of stormy weather.

“Some models are indicating that we could get into a wet weather pattern by the end of November,” Lindsey said, cautioning that those long-range forecast models should be taken with a grain of salt. “We can certainly keep our fingers crossed.”

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Gabby Ferreira is a breaking news and general assignment reporter at The Tribune in San Luis Obispo. A native of Houston, Texas, she was a reporter in Tucson, Arizona; Indianapolis, Indiana; and Palm Springs, California, before moving to San Luis Obispo County in 2016.