Air Should Get Cleaner, Maybe Wetter

You’d think it was December or something.

Forecasters say there will be a 40% chance of scattered showers late today, followed by a cold, windy weekend--and more rain possible by Monday.

That may seem somewhat difficult to believe since Thursday’s high temperature reached a balmy 74 in downtown Santa Ana, four degrees higher than normal. Relative humidity ranged from 93% to 34%.

Blame the gloomy turnaround on a couple of storm systems in the Pacific that are creeping this way.

“It won’t be heavy rain, maybe half an inch Friday night,” said forecaster Dan Bowman of WeatherData Inc., which provides forecasts for The Times.

Snow is expected in Southland mountains above 8,000 feet tonight, lowering to the 6,000-foot level by Saturday morning.

Air quality in Orange County today is expected to improve over Thursday, when unhealthful levels of nitrogen dioxide helped turn skies a murkey beige by midafternoon. While falling short of a first-stage alert, the pollutant’s moderate levels probably made life a bit uncomfortable for children, older folks and those with colds or lung conditions, a South Coast Air Quality Management District spokesman said.

A buildup of nitrogen dioxide--a common emmission from motor vehicles--is common in winter months when the prevailing ocean breeze weakens. In the summer, westerly winds off the Pacific blow the pollutant into the region’s interior where it cooks in the warm sun and becomes ozone.

While the approaching storm might dampen shopping plans, forecasters said it should help clear the air.

Bowman said that Monday’s showers will be preceded by some gusty winds over the weekend, when local temperatures are not expected to break out of the 60s.

Santa Ana was one of the few spots were the temperature topped the 70-degree mark Thursday. El Toro reported a high of 69, while San Juan Capistrano recorded 64 and Newport Beach 62. Lows in recent nights have been dipping into the upper 40s, except along the coast where they have been in the low 50s.

The change in the weather is being attributed to the movement eastward of a high-pressure area that has been protecting the area from Arctic-born storms that have been pounding the Pacific Northwest and Northern California, the National Weather Service said.

Surfers are one group looking forward to the next few days, when they can take advantage of heavy surf at west- and north-facing beaches.

Waves up to five feet are expected, down a bit from the six- to seven-foot waves that pounded the coast Wednesday, particularly at beaches in Los Angeles and Ventura counties. The water temperature Thursday was 60 degrees, but Huntington Beach lifeguard Claude Panis said the chilly conditions did not seem to deter many surfers.

“The waves were good at (Huntington Beach) and the crowds were out,” he said. “If the swell stays up, it’s going to be a good weekend of waves.”

With the approaching storms, small-craft advisories have been issued for the outer coastal waters today.