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12 FOUR SEASONS BREEZE | JUNE 2024 "Understanding the Weather" – A Series by Mel Zeldin, Retired Meteorologist This month marks the 50th anniversary of a unique event in smog history in Southern California. Back in the early 1970s, before the regional South Coast Air Quality Management District was formed, air pollution control efforts were in the hands of each county. I was hired by San Bernardino County in 1971 as their first- ever meteorologist to help the agency develop smog forecasts for the county. These forecasts were issued each morning for the following day. In those days, we called "smog alerts" when the level of ozone, a lung irritant produced by solar radiation interaction with chemicals emitted into the air from cars and industries, reached certain levels. In 1973, the California Air Resources Board enacted new smog regulations which defined three levels of what was called "smog episodes." Level 1, at 20 parts per hundred million (pphm) was primarily to avoid outdoor activities. Level 2 at 40 pphm was not only to avoid outdoor activities, but to reduce car emissions as a result of increased car pooling efforts. Level 3 at 60 pphm was considered hazardous exposure which could seriously affect human lungs. With a next-day prediction of a Level 3 episode, smog agency officials could ask the governor to declare a state of emergency for the region. In June 1974, meteorological conditions favorable to increased ozone levels began the week of June 24. By midweek, Stage 2 episodes were forecast and occurred primarily in the Inland Empire. As the meteorologist for the San Bernardino County Air Pollution Control District (SBAPCD), I looked at the weather models that were indicating worsening meteorological conditions, and the likelihood of higher ozone levels. On Wednesday, June 26, I looked at the weather model predictions indicating more severe weather the next day leading to a further increase in ozone levels. I forecast a Stage 3 episode for the next day. That forecast was released to the media. At that point, all hell broke loose. Our small agency was besieged from news reporters, many of whom helicoptered from other areas into San Bernardino. I received a call from the meteorologists at the California Air Resources Board (CARB) telling me that they did not agree with my forecast and wanted me to lower it to a Stage 2 and release an amended forecast to the media. At that point, I went to the director of the SBAPCD and told him what the CARB meteorologists wanted me to do. He asked me if I was confident in my forecast. I told him I was, and he supported my forecast. Ronald Reagan was governor at that time, and he was asked to declare a state of emergency for Southern California. He went on TV later that day, but only asked everyone to carpool as much as possible. No emergency was declared. The next day, conditions developed as forecast, and two cities, Upland and Fontana, both exceeded the Stage 3 level, reaching 71 pphm in Upland and 69 pphm in Fontana. And because smog controls on autos and industries began in earnest after that, levels continually began lowering such that it is virtually impossible to ever see such levels again. I therefore have the rather unlikely distinction of being the only meteorologist to ever forecast a Stage 3 episode in California and then have it actually occur. A Dark Moment In Southern California Smog History Four Seasons Resident Sounded the Alarm

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