Heavy smoke entered much of Southern California Thursday from distant wildfires in Northern and Central California.
Smoke from fires in the southern Sierra was pouring into the Los Angeles area and are expected to linger through Friday night, according to the National Weather Service. Some improvement is possible in southern areas Saturday as winds shift to the east, the agency said.
Surface smoke will be confined to the Antelope Valley Thursday, expanding into some parts of L.A. and Ventura counties Thursday night and Friday morning, the weather service said.
Drift smoke from the fires was also visible in Riverside and San Bernardino counties, Cal Fire reported.
Adam Roser, a meteorologist with the NWS in San Diego, said the smoke can travel hundreds of miles.
“[What] makes this kind of different is that these fires are generally closer to us, and all of that smoke is very thick,” Roser told KTLA. “So that’s why we’re kind of seeing the darker smokier skies, versus just a hazy sky.”
Several local fire authorities reassured the public that the smoke they were seeing was from the fires in the northern and central part of the state, and were not active fires in their area.
While the heaviest smoke will be present in the upper atmosphere across the region, impacts on surface air quality are expected in the San Bernardino, San Gabriel, and San Jacinto mountains, the South Coast Air Quality Management District said in a special air quality advisory Thursday.
As of noon, Good and Moderate air quality index (AQI) levels were being measured throughout the region, although elevated levels were expected in mountain areas starting Thursday afternoon and continuing until Friday afternoon.
The public is advised to avoid or limit outdoor activities in areas of smoke, as wildfires can often cause very high air pollution levels that are harmful to your health, AQMD said.
If you smell smoke or see ash due to a wildfire, AQMD advise you limit your exposure by taking the following steps:
- Remain indoors with windows and doors closed or seek alternate shelter.
- Avoid vigorous physical activity.
- Run your air conditioner if you have one and make sure it has a clean filter. Close the fresh air intake if your air conditioner has the option so that it is recirculating the indoor air to prevent bringing additional smoke inside.
- Create a space in your home with filtered air, by using a portable high-efficiency or HEPA air cleaner while keeping doors and windows closed
- Avoid using a whole-house fan or a swamp cooler with an outside air intake.
- Avoid using indoor or outdoor wood-burning appliances, including fireplaces. Avoid combustion sources inside the home such as candles and incense that could further degrade indoor air quality.
- If you must be outdoors in smoky conditions, keep it brief, and use a disposable respirator (N-95 or P-100).
An Air Quality Alert was also in place for San Joaquin, Stanislaus, Merced, Madera, Fresno, Tulare, and the Valley portion of Kern Counties due to the smoke.
Meanwhile, thousands of firefighters are battling the Windy Fire and the KNP Complex fire in the Sequoia area.
The KNP Complex blaze began as two fires ignited by lightning strikes on Sept. 9, and later merged into one blaze that has scorched more than 33,000 acres with zero containment as of Thursday, forcing the closure of Sequoia National Park.
To the south, the Windy Fire, also sparked by lightning, grew to over 43,00 acres with 6% containment Thursday, in the Giant Sequoia National Monument area of Sequoia National Forest.