Air quality for Napa County and the North Bay is expected to remain at unhealthy levels into the weekend, forecasters say.
The Bay Area Air Quality Management District on Thursday extended a Spare the Air alert through Friday, Communications Manager Kristina Chu said. The district’s meteorologists were assessing whether to extend the alert into the weekend, he said.
The district has issued an alert for more than 24 consecutive days, Chu said, shattering its previous record by more than a week.
Offshore winds have brought smoke from the August Complex fires burning in Mendocino National Forest – now the state’s largest wildfire ever at more than 470,000 acres – into the Bay Area, where it turned skies a dark, harrowing orange on Wednesday. Skies improved Thursday, but air quality continues to be harmed, especially in the North Bay because of its proximity to the fires.
Air quality for the entire Bay Area Thursday was categorized as “unhealthy for sensitive groups”, according to Chu. Larger pockets of the region – Napa Valley and the North Bay included – were moving into the “unhealthy” category, Chu said, which starts at 150 on the AQI (air quality index). The index tracks the concentration of pollutants and particles in the air.
At that level, the air does not necessarily need to smell like smoke to have harmful side effects, she added. Individuals with preexisting respiratory conditions should be cautious about exposure; even healthy individuals may begin to experience symptoms if spending elongated periods of time in the outdoor air.
This quality could last into the next week, Chu said.
“We don’t anticipate it improving until containment actually happens, and we don’t see that happening before next week,” she said.
The weather forecasting service Accuweather momentarily caused some stir Thursday when it forecast an AQI between 800-900 for northern portions of Napa County, including Angwin, over the weekend and AQI in the 500s for the city of Napa. (Those numbers would surpass completely the EPA’s air quality monitoring scale and put the county past “hazardous” into the “extreme” category).
Accuweather Senior Meteorologist Alan Reppert said the forecast listed on the website was “too high” and confirmed that it was likely not accurate.
“I would expect (AQI) to be somewhere between 100 and 200,” Reppert said, adding that AQI of between 150 and 200 was about the maximum for the region.