Mild Santa Ana Will Perk Up the Weekend

Sunshine and warm winds are expected to dry the air and promote daytime highs in the 70s and 80s this weekend, as a mild Santa Ana condition moves in to dominate San Diego County weather.

According to the National Weather Service, humidity will begin falling today, and temperatures will gradually rise to unseasonably warm highs by Saturday.

A high-pressure system building off the coast Thursday was forecast to move into Nevada this weekend and send winds back to San Diego County from the northeast, forecasters said.

“As the winds come down the mountains, they will warm up and dry up the county,” forecaster Wilbur Shigehara said. “It will be a nice weekend for outdoor activities.”

Humidity that was 45% to 55% Thursday afternoon at Lindbergh Field could drop as low as 15% by Saturday.

Temperatures that have been hovering in the 60s in most areas of the county should reach the 70s today and the 80s Saturday, Shigehara said.

Although forecasters were not certain how rapidly the Santa Ana condition would develop, gusty winds are predicted for mountains and deserts over the weekend.

“Winds will be strongest in desert areas. They will be heightened by the Santa Ana condition and a low-pressure system in Arizona. The two will create a greater pressure difference in East County,” Shigehara said.

“People going to the deserts this weekend ought to listen to the latest forecast. It may not be a very pleasant weekend there.”

Forecasters predicted winds up to 25 m.p.h. in mountains and deserts and up to 20 m.p.h. along coastal waters.

Surf is expected to be mild at two to four feet, but winds from the southwest and the northeast may approach small-craft advisory status along coastal waters.

Other areas of the county should have weaker winds.

Although daytime highs may be 10 degrees above normal, temperatures will drop quickly when the sun goes down. Lows will be cooler than normal and may approach freezing in the mountains, Shigehara said.

“Temperatures in the upper 20s Friday night could cause damage to blooming apples in Julian,” Shigehara said.

Under clear skies, lows are expected to be in the 50s along the coast, in the 40s in both inland valleys and the desert, and a chilly 20 to 35 degrees in the mountains.

High temperatures at the beach of 70 today may reach 73 by Saturday. The ocean water temperature has warmed slightly, to about 62 degrees.

Coastal strip and inland highs of 68 to 76 today are expected to reach the low 80s Saturday.