New, strict wood-burning rules didn't stop anyone in the San Joaquin Valley from lighting a fire in the fireplace over the weekend. But a burn ban should have been enforced Sunday in Fresno County.
In central Fresno, an air monitorshowed pollution above the trigger level for restricting burning in open fireplaces and old wood-burning heaters.
Like most things connected to wood burning in fireplaces, the forecast is a sensitive subject.
In the past, I’ve heard strong opinions on both sides. Some people say the the San Joaquin Valley Air Pollution Control District isn’t protecting people enough in the forecasts. Some say the district is bending over backward to stop wood burning.
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The district says it gets more than 80% of forecasts right.
The forecasting continues to evolve, officials said. But this is a complex process, and the results are not always right.
What’s involved? There's basic meteorology — barometric pressure, wind speed, vertical air mixing heights, surface temperature, relative humidity and precipitation.
The forecasts also are supposed to be made separately for eight counties from Stanislaus to the Valley portion of Kern. They take in 30-plus monitoring sites. The district forecasters also must consider each year how the public changes its behavior to reduce pollution.
There’s one other factor that might be confusing. The threshold for banning burning in open fireplaces and old heaters is a forecast of 20 micrograms per cubic meter of air. That figure is a daylong average, not a single hourly peak.
Keep your eye on “Check before you burn” on the district’s Web site over the next several months.