Smog Experts Predict Fewer Stage 1 Alerts

There will be fewer “very unhealthful” days--or smog alerts--this summer than last, air quality experts announced Tuesday.

“We should see a return to more normal weather patterns, and as a result, fewer Stage 1 ozone episodes this summer than last,” said Joe Cassmassi, the South Coast Air Quality Management District’s senior meteorologist.

A Stage 1 episode occurs when ozone levels reach 0.20 parts per million, or 200 on the Pollutants Standard Index. Air quality is then considered very unhealthful and people are urged to avoid vigorous outdoor exercise.

“Our air quality this summer may not be as good as it was in 1997, when El Nino’s cooler temperatures and unsettled conditions brought unusually clean conditions,” Cassmassi said. “But we should see a return to the long-term trend toward reduced peak levels of ozone and fewer days violating federal health standards for the pollutant.”

In 1997, there was one Stage 1 episode. But that shot up to a dozen last year, with most of them in the central San Bernardino Mountains.

So far this year, there have been two violations of the federal standard for ozone, which is 0.12 parts per million or 100 on the index.

One occurred April 18 in downtown Los Angeles and in the central San Bernardino Mountains. The other was Friday in the central San Bernardino Mountains.

La Nina has brought winter-like weather into the spring and given Southern Californians relatively good air quality so far this year, Cassmassi said.

Last summer, the weather phenomenon was credited with bringing extremely strong high pressure systems, with stagnant atmospheric conditions across the region, and an increase in Stage 1 episodes in the San Bernardino Mountains, he said.