Smoke, bad air quality returns to Bay Area this weekend: Here's when it will arrive

ByAlix Martichoux KGO logo

Sunday, September 20, 2020

Wildfire smoke, hazy conditions back in Bay Area

The smoke forecast for the Bay Area shows wildfire smoke coming back to the region and air quality getting worse in over the weekend and into Monday. Air quality is expected to be moderate, Meteorologist Drew Tuma says.

SAN FRANCISCO (KGO) -- It's been a blissful few days of clear skies in the Bay Area, but air quality took a turn this weekend. Smoke was forecasted to make its way back over the region this weekend and has prompted an air quality advisory in the Bay Area.

The advisory will stay in effect through Monday.

LIVE SMOKE TRACKER: Track Bay Area air quality levels

"Waking up Saturday morning, the winds are shifting, coming out of the north and bringing the North Complex and the August Fire Complex smoke," says ABC7 News Meteorlogist Mike Nicco. "About half of us will be covered by Saturday evening in haze and it just keeps getting thicker as we head through Sunday."

Smoke will turn hazy as a wind shift occurs in the northerly direction. Smoke will then drift into the North Bay from the August Complex Fire and then spread across the rest of the Bay Area.

The air quality advisory is in effect Sunday and Monday because of wildfire smoke expected to drift into the Bay Area, bringing hazy skies mainly to the North Bay. The Bay Area Air Quality District says the air is not expected to be unhealthy despite the advisory.

Here's how the smoke timeline breaks down for the Bay Area:

The North Bay will be the first region affected, with smoke moving in overnight Friday into Saturday. As the day goes on, the smoke will "slide into the bay, into the Peninsula and the East Bay," says Nicco.

Only the South Bay may be spared Saturday morning and during the day.

"By Saturday evening, it should be covering just about everywhere but the South Bay."

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Things only get worse from there Sunday, when most of us should expect to wake up to hazy skies. (Though the best chance of clear skies is once again in the South Bay Sunday.)

"Just about everybody" will be shrouded in smoke Monday until relief finally arrives again on Tuesday, says Nicco.

"Autumn arrives at 6:31 a.m. and it ushers in clean air," Nicco says of the autumnal equinox.

So how bad will air quality be?

Thankfully, we aren't looking at orange skies or apocalyptic conditions this time around.

The Bay Area Air Quality Management District issued a Spare the Alert for Saturday due to poor air quality in the inland East Bay and North Bay, but just how bad the air quality will be on the ground depends on a few factors.

This trend looks to continue into Sunday as well, but luckily winds will remain generally light.

"There will be smoke in the middle parts of the atmosphere," says Nicco. "The key will be how much will work into the lower layer."

Meteorologist Drew Tuma predicts moderate air quality (PM 2.5 levels between 51-100) across the Bay Area on Sunday.

Monday is trending slightly cooler with better air quality.

Watch Meteorologist Drew Tuma's Saturday evening smoke forecast in the media player above.

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