Lumps of ash bigger than a human hand filled the skies that turned orange from the blaze located northeast of the region. Some lumps looked fibrous while others resembled shredded bark. Among the ash were burnt leaves.
Authorities advised residents to stay indoors or wear protective masks to minimize inhaling particulate matter. Weather experts said air quality in the Bay Area would remain bad throughout the rest of the week.
The Glass fire has burned more than 50,000 acres and is two percent contained as of Wednesday evening, according to the California Department of Forestry and Fire Protection (CalFire). Nearly 70,000 residents have been forced to evacuate as state and federal firefighting crews attempt to suppress the fire that threatens to destroy more than 26,000 structures.
Several residents reported that the ashfall came with larger, chunkier lumps of ash and debris. A Facebook post from the weather blog Live Storm Chasers shared photos of huge, charred flakes of ash captured by a Santa Rosa resident, Morgan Balaei. One photo showed a charred flake that completely hid Balaei's hand from view while another showed the sky peppered with macroscopic soot. Balaei said that the ash was small at first but got larger as the fire progressed.
Other residents reported picking up burnt bay leaves in their backyard. "I have it in my backyard, I even found burned leaves which is terrifying," one Santa Rosa resident said Monday morning.
The ashfall continued the next day in Sebastapol seven miles west of Santa Rosa. "I was shocked at how much ash is in Seb this morning... a 100 burnt bay leaves in the yard," said Tuesday by a resident in the area.
It's still unclear what material was burned for some of the flakes to become so big, though the ashfall was likely caused by the Glass fire. Bay Area meteorologist Rob Mayeda confirmed that ashfall is approaching Santa Rosa from the east in the midst of hot, dry and windy conditions.
Authorities warn Bay Area residents to avoid going outdoors as much as possible as poor air quality is in the forecast until Friday due to the Glass fire smoke.
Mike Nicco, a meteorologist at ABC7 News, said that the region's air quality index improved on Tuesday morning but is expected to deteriorate in the coming days. Air quality conditions in the North Bay will be the worst as it's closest to the fire. As other areas see improvements toward the end of the week, most of the smoke will return to North Bay after the sea breeze temporarily clears the air.
The Bay Area Air Quality Management District (BAAQMD) already extended the Spare the Air alert through Friday but Nicco expects that to get further extended through the weekend. "Keep those N95 masks handy," he said.
Residents are not allowed to burn wood or any solid fuel whether indoors or outdoors during a Spare the Air alert. Jack Broadbent, the executive officer of the BAAQMD, urged residents to monitor air quality and avoid going outdoors if the smoke exceeds tolerable levels. Meanwhile, Tina Landis, also of the BAAQMD, added that the smoke is particularly harmful for people with asthma or any respiratory problem.
“Smoke impacts are the biggest concern because it can have immediate health impacts. There’s particulate matter, that’s so fine, PM 2.5 which gets very deep into your lungs,” Landis said. (Related: California wildfire smoke may have contributed to over 1,000 deaths (so far).)
Disaster.news has more on the wildfires of California.