Dry weather and a lack of wind in Merced County mean the smoke wafting in from the Camp Fire in northern California isn’t leaving quickly, according to weather officials.
The Central San Joaquin Valley’s shape makes it a natural destination for the smoke, officials said, and without anything to push it out, the smoke is expected to linger at least until the weekend.
“There’s not a whole lot of force pushing it,” meteorologist Andy Bollenbacher said. “We have in the Valley a bathtub effect, the smoke just collects. To really get that out you need a cold front to come through.”
There may be a cold front coming this weekend but it’s too far away to predict with real certainty, according to Bollenbacher, who works for the National Weather Service in Hanford.
The Camp Fire has killed at least 42 people in the Paradise area of Butte County with more than 200 people missing as of Tuesday. The wildfire had burned 125,000 acres and more than 7,600 structures, Cal Fire reported.
On Saturday, the San Joaquin Valley Air Pollution Control District issued an air quality alert that will remain in effect until the surrounding wildfires are extinguished. The alert was issued for Merced, Stanislaus, San Joaquin, Madera, Fresno, Kings and Tulare counties, along with the valley portion of Kern County.
Exposure to particle pollution can cause serious health problems, aggravate lung disease, cause asthma attacks, acute bronchitis and increase the risk of respiratory infections, according to the weather service.
Residents with heart or lung disease should follow their doctor’s advice, and older adults and children should avoid prolonged exposure to the smoky air and strenuous activity.
Overnight temperatures for the next week are expected to dip to the mid- to high 30s.
Cory Mueller, a forecaster with the weather service in Sacramento, said the cold weather has little to do with the trapped smoke. “Once the sun sets, the temperatures seem to fall quite a bit,” Mueller said. “We just really had dry air... When we have light winds and dry air, we see cooler temperatures.”