Freeze Due Tonight, Then Big Storms

The clear and mild days and borderline-freezing nights expected today and Saturday will differ sharply from the stormy and cold conditions expected to roll in Sunday and last through the middle of next week, the National Weather Service said.

A Santa Ana condition will continue through at least Saturday night, forecaster Wilbur Shigehara said, keeping San Diego skies clear and daytime temperatures pleasant. A travelers’ advisory in the mountains and deserts for gusty winds will remain in effect through at least tonight.

At some point on Sunday, a storm approaching from the Gulf of Alaska will bring heavy showers and possibly thunderstorms and light snow in the foothills, according to Shigehara.

“Southern California will bear the brunt of this new storm,” he said. “It will stall here for at least two or three days, and our long-range charts are hinting that it will produce a lot of heavy showers, with thunderstorms entirely possible. There’s some very cold air associated with it, and the snow levels could drop down to 2,000 feet.”

That could mean an inch or two of snow in the foothills of Ramona, Alpine and Campo, Shigehara said.

A frost warning will be in effect for San Diego’s agricultural areas tonight and Saturday night, where temperatures are expected to dip to 24 degrees in the coldest inland valleys, Shigehara said.

Such a warning has not been issued since Jan. 17, when overnight temperatures dipped to 18 degrees in the coldest inland valleys. The rare below-freezing temperatures of last month resulted in a 40% loss of the total San Diego avocado crop, according to Shigehara.

“Of course, some of the fruit can’t be damaged any more, especially in the low-lying groves,” he said. “A serious cold could kill the foliage and the trees themselves, and the already-ruined fruit would fall off, but this is not as serious a cold as we got before.

“Temperatures like 24 degrees in the coldest areas happen pretty much two or three times every year and they (farmers) can handle it. Farmers in most areas will only have to contemplate frost protection, not actually resort to it. There will be large temperature differences between low-ground and high-ground orchards, with the high-ground areas relatively safe from frost.”

Nighttime temperatures will slowly begin to moderate after the clouds roll in Sunday, Shigehara said.

Beach and inland daytime temperatures will range from 64 to 69 degrees today and Saturday, nudging down a couple of degrees when the storm arrives Sunday. Coastal lows will be in the upper 30s, with inland lows in the mid-30s in most areas.

Surf will be three to four feet, with breakers up to six feet likely on Sunday. Ocean temperature will remain near 59 degrees.

Mountain highs will be between 38 and 45 through Sunday, with lows dipping to the 18- to 28-degree range. Deserts will have highs in the low 70s, with lows in the upper 30s through the weekend.