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How's the Weather? In Southern California, It's Wet, Dry, Hot, Cold

Second of two parts

October 26, 1986|DICK RORABACK | Times Staff Writer

Whether wallowing breech-deep in backyard rainwater or contemplating a navel painted puce by the savage sun of August, it helps to remember that Southern California weather is demonstrably the best in the world. Most of the time.

How hot is it, Johnny? How cold, wet, dry, windy, calm? Like the storied blind men attempting to describe an elephant, it all depends on where you are, and when. On the whole, the Southland is a climatic cornucopia. Dig the desert air? Move to Glendora. Seduced by the sea mist? Move to Malibu. Partial to scorching summers? Try the valleys. Semi-nippy winters? Again, try the valleys. Ah, the valleys. . . .

Southern California's valleys not only have weather systems all their own, they have systems within systems. As a rule, though, they are far and away the hottest places to live in the summer--and, curiously, the coldest in the winter.

Blockaded by surrounding hills, cut off from the soothing salve of the offshore freshets, the Southland's valleys just sit there and take it, unwilling exemplars of what California would be without the Pacific High.

"Valley weather--all of the onshore weather--depends on how strong the seabreeze is," explains Art Lessard, meteoroloist-in-charge of the National Weather Service in Southern California. "It's Mother Nature's air conditioner, and it's tricky. It can be going full blast down at the beach, for example, but often enough, somewhere between here (Westwood) and Ocean Boulevard in Santa Monica, it just shuts off. It might make it to Bundy and that's it.

"So the summer temperature at the Civic Center hits 90-95 before noon, when the sun isn't even at its apogee. Around 2 p.m., when the seabreeze picks up, the flags start turning around and the temperature drops to 88, 85, 77. . . ."

"Ironically, the hotter it gets inland, the cooler it's liable to get. The land is warmed by the sun, heating the air above it. The warm air rises and has to be replaced by something. Into the vacuum rushes the cooler sea air, a nice balancing act that can extend all the way to the Mojave Desert--unless, of course, the wind is blocked by the mountains.

"In the valleys, though, sometimes in the summertime they can be as bad as Death Valley," says Lessard, who prudently lives in

Brentwood, just a few landscaped miles downwind from the ocean.

And just to rub it in, what valley residents spend on Freon in the summer is compounded by outlay for natural gas in the winter.

A common misconception is that the valleys, without much of a breeze, should be warmer in the winter, which is a crock of chilblains. As always in Southern California, the answer is blowing in the wind.

"During the winter months," Lessard says, "the San Bernardino Valley, the San Gabriel Valley, east toward Riverside can get quite cold, primarily because little or no air is moving. On a good cold night, it'll be about 50 degrees in the parking lot here in Westwood, while to the east, it'll drop down to 29, 28 degrees.

"The air off the ocean is warmer, especially at night. In the sheltered valley areas, the still air will drain downward and settle, as in a bowl. It cools off, gives its heat to the atmosphere, and just sits there."

At least, then, the valleys aren't subject to those howling winds that lift roofs, tear the eyes, weaken the moral fiber and blow all the equipment into the swimming pool? Don't bet your bippy.

"The places where the wind blows most constantly, especially in the summertime, are the beaches; 30-to-35-mile-an-hour winds are not uncommon," Lessard says.

Where you get your real blasts, though, are through the mountain gaps, the canyons, the riverbeds, "or, as we call them in New Hampshire, the gulches or the notches.

The Truth About Santa Anas

"You don't find too many areas where the wind blows stronger than through the Cahuenga, Newhall and Cajon Passes during a Santa Ana episode. The northeast-southwest passes (through the valleys) are the worst. Why? Because the Santa Anas whistle down from the northeast. . . .

"I know, I know," Lessard says, reading another raised eyebrow and anticipating the question. "I read it in the papers and I hear it on the radio all the time: 'The Santa Ana blows from the south.' Well it just ain't so.

"It was named Santa Ana, back in the 1850s, because it blows especially strong through the Santa Ana Canyon. Eventually, the name 'Santa Ana' was used to describe these strong northeasterly winds wherever they occurred. Sure, the wind comes from the desert, but from the northeast desert--the Mojave and even farther away; from Nevada, actually, and over the southern Sierra.

"There are probably 300 variations in the world of what we call the Santa Ana--the foehn, the mistral. . . . Here, they occur primarily in the winter months, late fall into early spring, though we can get them at all times of the year. And here again, against popular misconception, they can be very cold winds."

Air Flows Downhill

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