Fog rolls in, worsening air quality in Los Angeles Basin and delaying flights

Heavy fog cut visibility, snarled air traffic at Hollywood Burbank Airport on a busy travel day and worsened air quality in the Los Angeles Basin on Sunday.

The Air Quality Management District extended a no-burn order for another 24 hours, prohibiting most residents in the region from lighting fireplaces, bonfires or campfires or burning wood by any other means through Monday at 11:59 p.m.

The wood-burning ban covers Orange County and the non-desert areas of Los Angeles, Riverside and San Bernardino counties, the AQMD’s order said. The reason for the ban is because wood smoke contains tiny particulates that can lodge in the lungs and cause asthma attacks and other health problems.

“We’ve experienced many days of poor air quality since November,” said Kim White, a spokeswoman for the AQMD. “While we frequently experience poor air quality this time of year when we have stagnant conditions, we’ve experienced more days of high fine particulate matter than normal this winter.”

More than 60% of the flights at Hollywood Burbank Airport — the second busiest in Los Angeles County — were either canceled, delayed or diverted to regions with better visibility through early afternoon Sunday because of the foul weather, according to the airport’s flight data. The rate of disruption was far lower at Los Angeles International Airport.

Nerissa Sugars, public information officer at Hollywood Burbank Airport, said conditions were normal for this time of year. The airport, in the shadow of the Verdugo Mountains, has endured intermittent foggy conditions over the last few weeks. Whether fog will disrupt airport operations in the coming week, she said, “is day-to-day.”

“When there’s no visibility, there’s no visibility,” she said Sunday. “It’s not a good idea to take off in these conditions.… Today, because it’s a weekend, the airport is even more affected because more people are traveling.”

The best advice for travelers this time of year, Sugars said, is check with your airline the night before your flight and again before you leave for the airport the next day.

Joe Sirard, a meteorologist with the National Weather Service, blamed a low, strong marine layer, also known as an inversion, for the persistent fog and bad air.

“The marine layer is a stable layer of air,” he said Sunday. “It does not allow the air [below it] to move around and keeps the air close to the ground, without any mixing. Clouds form below the inversion and can’t dissipate until the sun burns them off.”

If the inversion layer is strong, he said, “it’ll trap smoke.”

By midday Sunday, Sirard said, the fog had largely cleared out of Burbank, leaving behind a lingering haze, “but they should be able to get planes off the ground.” And “we don’t expect a repeat tonight” of the heavy inversion layer and dense fog.

Low clouds and some fog are forecast along the Los Angeles County coast into Monday morning. Sirard said he did not expect them to move into the valleys. It should be mostly sunny during the day.

And Tuesday, expect some light precipitation — enough for a rain coat, maybe, but you can probably leave the umbrella home.

Think “a few hundredths of an inch,” Sirard said, and then it will be “partly cloudy to mostly sunny” Tuesday afternoon.