Conditions remained dry and hazy in Sacramento on Tuesday, as smoke from the Camp Fire continues to blanket much of Northern California, and a number of factors are making it difficult to estimate when the smoke might let up, National Weather Service officials said.
It is likely that smoke spread will ease up as winds die down, but smoke won’t leave Sacramento or the Sacramento Valley entirely until Camp Fire activity decreases more, NWS Sacramento forecaster Jim Mathews said.
“We expect much lighter winds today and through the rest of the week,” Mathews said Tuesday. “And there’s still some fire activity on the (Camp Fire), so that’s the unknown.”
According to satellite forecasts tweeted by NWS Sacramento, near-surface smoke will persist through Wednesday; aside from the thickest smoke in the immediate vicinity of the still-burning, 125,000-acre wildfire, winds will push the heaviest smoke north of Chico late Tuesday, much of it expected to concentrate in the state’s northeast corner, between Redding and Susanville.
Then, around midday Wednesday, winds are expected to take some of the moderately heavy smoke southward near Yuba City and Marysville.
Mathews pointed out that satellite images of the smoke are not perfectly reliable for forecasting smoke because natural cloud cover can block the low layers of it — and for human impact, the lowest layers are the ones that matter most.
The other unknown is precipitation. Seven-day forecasts by NWS online did not yet show conditions for Nov. 20 or beyond, but Mathews and other weather websites predict a chance of precipitation midweek next week.
Mathews said if rain falls in Sacramento, it would likely happen on Thanksgiving or the Tuesday or Wednesday preceding it. Mathews added that it wasn’t yet clear how heavy that precipitation, if it falls, would be in Northern California, so its potential to douse the Camp Fire and aid the 5,000-plus firefighters assigned to it is not yet clear.
More detailed smoke forecasts further into the future depend on wildfire activity, which has calmed as the winds that promoted spread and red flag warnings statewide are expected to die down.
The Sacramento region’s Spare The Air website shows the Air Quality Index reading for Tuesday to be 169, with an AQI of 174 predicted for Wednesday; both readings are defined as “unhealthy,” with readings 200 or above marked “hazardous.” AQI readings about noon Tuesday were hazardous in Yuba City and Gridley. Some parts of Sacramento observed AQI readings as high as 367 Saturday.
In the meantime, smoky conditions have had an impact in the city of Sacramento and surrounding areas, canceling many events. The city has offered free respirator masks to citizens. Sacramento State closed its campus Tuesday, and UC Davis canceled all classes the same day.
The Amazon fulfillment and warehousing center at Sacramento International Airport has been closed to workers as a safety precaution since Saturday afternoon, potentially leading to delivery delays in the region. More than 2,000 employees work full-time at the location.