Winter Chills to Return With Pacific Storm

Dry, summer-like air Monday banished winter weather, replacing it with a Santa Ana condition, but forecasters warned that a storm from the Pacific and chilled air from the Yukon are expected to restore January weather in San Diego.

Surf up to 12 feet is expected to pound the coast today and Wednesday, and the arctic air will invade the county Thursday, National Weather Service forecasters predicted. An advisory was issued warning wave watchers and coastal property owners of large swells through Wednesday. Growers were warned that freezing temperatures are expected to arrive Thursday.

Waves reached eight feet Monday at Oceanside beaches and at the entrance to Mission Bay. High tide will be 6.4 feet at 7:50 a.m. today and 6.5 feet at 8:24 a.m. Wednesday.

“We have to remember not everyone has the highest regard for some of these warnings,” forecaster Richard Stitt said of the advisories. “People should enjoy the waves from a safe distance.”

A storm about 1,500 miles off the coast, moving toward San Diego from Hawaii, is generating the waves, forecast to be three to four times higher than the average 2-to 3-foot San Diego swell, Stitt said.

The flow of moist air from the ocean also will overcome the Santa Ana condition today, restoring normal humidity. Relative humidity was 15% Sunday and 18% Monday. It should return to a daytime range of 50% to 60% today, Stitt said.

The Pacific storm, although it is expected to weaken as it approaches land, may also bring rain toward the end of the week, Stitt said.

Forecasters are closely watching a weather pattern that may bring “dangerously low” temperatures to agricultural areas by Thursday. Meteorologist Wilbur Shigehara issued a “special warning” to growers Monday.

“The upper wind patterns indicate a very cold flow developing. These temperatures could be very destructive to trees,” Shigehara said.

“It is the farthest thing from people’s minds when the weather is so nice and sunny,” he said of the cold front, “so I issued an advisory for growers to clean up their heaters and wind fans, get fuel and make sure their crews are ready.”

If the chilled air does arrive as forecast, the snow level could drop as low as 1,000 feet, Shigehara said.

Temperatures should continue to be higher than normal today and begin to drop Wednesday.