Merced County residents who noticed the smoky air Monday afternoon and evening may have to get used to it, at least for the rest of the week.
According to the National Weather Service, a strong ridge of high pressure has engulfed the Central Valley and is expected to hang out for the next several days.
Kevin Durfree, meteorologist for the National Weather Service in Hanford, said smoke from fires in the mountains and from the vineyards of northern California are traveling with winds from the east, mixing in with the air.
The smoke has a tendency to settle in the Central Valley floor at night, he said.
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According to the San Joaquin Valley Air Pollution Control District's Real-Time Air Advisory Network, the pollution content in the air hiked to a "very unhealthy" Level 5 at about 6 p.m. Monday before shooting back down to Level 3 "Unhealthy for Sensitive Groups" at 10 p.m.
"There's very little airflow in the Valley right now," Durfree said, adding that it may take several days until the Central Valley gets some fresh air.
People, especially those with sensitive conditions such as asthma, should plan to spend as little time as possible outdoors.
"The (high pressure system) will sit over us for many more days," he said. "The smoke doesn't have much chance to leave."
Tuesday’s forecast is clear skies with a high of 86 degrees, according to the NWS.