Coastal Fog, Low Clouds Call Halt to Heat Wave

As promised, Southern California’s punishing heat wave broke Tuesday with the arrival of a coastal fog bank and low clouds that appeared determined to hang around for a few days.

“We’re not expecting the heat to return any time soon,” said Patricia Cooper, meteorologist for WeatherData, which provides forecasts for The Times. She said the weak onshore flow should continue for a while.

The downtown Los Angeles temperature reached 86 degrees, which had been predicted by the National Weather Service. That was nine degrees lower than Monday’s Civic Center high, which had followed the record-shattering 108-degree marks of Saturday and Sunday.

The temperatures dropped as the coastal trough drifted inland, no longer allowing a high-altitude high-pressure system to push hot desert winds toward the Southland.

The overnight low Tuesday was 66. Relative humidity ranged from 90% to 46%.

Fair but Hazy

As for today and Thursday, the forecasters said, there should be late-night and morning low clouds; otherwise fair but hazy with high temperatures around 80 degrees. Lows should be in the mid-60s.

Even the valleys are expected to be comfortable in the low- to mid-80s.

The only remaining really hot weather will be in the southern deserts, the weather service said, with maximum readings from 98 to 104.

Even the air was improving, with the South Coast Air Quality Management District predicting a slight upgrading from unhealthful to moderate in most areas of the Los Angeles Basin today.