Cooler Weather to Clear Away Smog

After a nasty blitz of smog-drenched air, Valley residents should breathe easier this week as a low pressure system cools temperatures and weakens the inversion layer, meteorologists forecast Monday.

“I don’t think we’ll see any very unhealthful levels (of smog) the rest of the week,” said Kevin Durkee, a meteorologist for the AQMD.

At the end of last week, some of the foulest air of the year covered the Valley and most of the Southland. Thanks to a high pressure system that created all the ingredients for a smog blanket, the region had stagnant air flow, strong sunshine and a persistent inversion layer.

In Reseda on Saturday, the smog almost reached first stage, or very unhealthful levels, equivalent to over 200 on the Pollutant Standard Index (PSI). Smog levels topped 200 in Santa Clarita on Saturday.

But by Monday the weather pattern now over the Southland was one that has prevailed most of this summer and is far less amenable to creating smog. “The West Coast is under a trough of low pressure that gives us cooler temperatures and lifts the inversion,” Durkee said. “The air quality is not likely to be bad in the conditions we have now.”

The first beneficial effects were felt Sunday as smog levels in the Valley dipped below 100, equivalent to good-to-moderate air quality. Durkee said levels would be similar or even lower Monday.

He added that the Southland should stay relatively smog-free later in the week as another ripple of low pressure--with temperatures hovering around 80 degrees--comes through the area.