As the Red Salmon and August Complexes burn in the Emerald Triangle, Mendocino County skies have darkened with smoke and ash while residents have been encouraged to stay indoors due to unhealthy air quality. John Wood, a meteorologist with the National Weather Service office in Eureka, said weather forecasts offer no reprieve from the unhealthy air extending potentially well into early next week and predicts Humboldt County skies could soon darken too.
Wood predicted smoke would begin to settle in the valleys and lower elevations of Humboldt County as the winds from an off-shore gale decrease. Wood described these dominant winds helping Humboldt County avoid smoke-inundation in the last week but as the gale settles, so will the smoke.
A joint message from the North Coast Unified Air Quality Management District and partners described their predictions for smoke in Humboldt County:
[C]oastal areas are expected to remain “Good” to “Moderate” with possible periods of “Unhealthy for Sensitive Groups” as offshore winds push smoke towards the coast in the afternoon and overnight. Southern Humboldt County is expected to see “Good” to “Moderate” with possible periods of “Unhealthy for Sensitive Groups” depending on conditions. Orleans, Hoopa, Weitchpec, and areas along the river drainages may experience “Good” to “Moderate” with afternoon and overnight periods of possible “Unhealthy for Sensitive Groups” to “Unhealthy”. depending on conditions and proximity to the fire.
Wood explained that models indicate an extreme ridging event accompanied by high pressure will occur later this week into early next week which could lead to record temperature and stagnant air essentially trapping the wildfire smoke in the region.
Another contributing factor to the smoke staying in the area, Wood explained, is a southern return flow along the Mendocino Coast which he said: “pins the smoke along the coastline.”
Wood suggested that the Ukiah Valley could see short periods of southerly winds throughout the next few days but in general, the winds will be calm and the smoke will continue to settle.
Wood said the smoke is a direct result of the fires burning northeast of Mendocino and Humboldt Counties and will continue until there is a significant reduction in the size of the fires. Wood said simply, “The smoke is here to stay until the fires are under control.”
The National Weather Service states, “Smoke from wildfires can cause eye and throat irritation, coughing, and difficulty breathing. People with respiratory diseases, heart disease, young children and older adults are most at risk.”