Another layer of thick haze greeted Bay Area residents with the sunrise early Thursday, but forecasters said the dirty skies weren’t quite as dirty even if they weren’t clean.
The trend will last at least until Friday before weekend conditions lead to much clearer skies, according to the Bay Area Air Quality Management District.
The district extended its Spare the Air alert for the region into the last day of the work week, marking the third straight day that Bay Area residents can’t burn wood or manufactured fire logs in any wood-burning place such as a fireplace or firepit.
The district has issued nine such days in 2023. They are caused by various weather and atmospheric conditions that prevent the natural clearing of the Bay Area’s air or bring in foul conditions, as was the case this week.
Smoke from wildfires burning in Oregon and in Humboldt and Del Norte counties in Northern California continued to billow toward the region from the coastline Thursday. But even as the haze hung in the air in many areas, it was not quite filled with as many pollutants as there were Wednesday. The improvement was likely to continue, albeit slowly, through Friday and more over the weekend.
“We do expect air quality to improve more significantly beginning on Saturday, as wind patterns are forecast to move smoke away from the Bay Area,” district spokesperson Kristina Chu said in an email.
By noon Thursday, the district’s Air Quality Index readings showed a regional high of 113 at Oakland’s Laney College, with readings over 100 in San Pablo, Redwood City, with other communities like Pleasanton, Concord, San Jose and Livermore reading over 100 at earlier points in the day.
A figure from 101-150 means the air is unhealthy for children, seniors and those with breathing issues. E
On PurpleAir, which offers more up-to-the-minute readings from different monitoring stations, the highest AQI readings at 1:30 p.m. was in Hayward, with recordings of over 100 across most of the inner Bay Area.
A shift in winds Wednesday into Thursday toward a northwestern direction — meaning they move in a counter-clockwise pattern over the region, pulling smoke into the area before cycling it out to the ocean — created the possibility that more smoke from wildfires burning in southern Oregon and northwest California could billow into the region from the coastline, according to weather forecasters.
The wind pattern and direction is expected to change by Friday and take the smoke away from the region, forecasters said.
The gusts Thursday brought with them a red-flag warning set to last much of the day for fire danger in the northern and eastern parts of Napa County bordering the Sacramento Valley.