Rain Expected, but It Won’t End Drought : Weather: The high-pressure system that deflected storms to the north yielded a bit and experts are predicting three or four storms this week.

California’s “storm door”--mostly barred for months by persistent high pressure over the Southwest--cracked open a bit Tuesday, admitting a welcomed weather system expected to produce three or four rainstorms through the weekend.

If the forecasters are right, it should be raining today in many parts of Southern California, with half an inch to an inch of precipitation in coastal regions and two to three inches in mountain areas, with snow at high elevations.

“Rain coming. . . . We hope,” the National Weather Service said in a special weather statement issued Tuesday.

Light rain was expected to move onshore in Santa Barbara County on Tuesday night, then spread over Southern California coastal plains and mountains today, with a chance of showers in the deserts.

Residents from Central to Northern California as far as Eureka on the coast north of San Francisco were also told to expect rain, with snow in the Sierra Nevada above 8,000 feet, lowering to 6,000 feet as colder air moves in later in the week.

But, the weather service’s statement offered more than prospects of a single rainstorm:

“Of greater importance in making a dent in the drought . . . the upper air pattern shows signs of opening up the storm track across the eastern Pacific, allowing a series of storms to strike this area during the next several days.”

Meteorologist Steve Burback of WeatherData Inc., which provides forecasts for The Times, expected “at least two or three other storms” to come with the storm track and into the state during the rest of the week.

Burback said the storm waves were moving straight at California, instead of being blocked to the north by the long-lived high-pressure system that has persisted in the Southwest.

But Burback did not think the storm series will be a drought-buster.

“It really won’t replenish the lakes,” he said.

Drought specialist Dean Thompson of the state Department of Water Resources greeted wet-weather predictions as the “most encouraging news we’ve had in almost a month.

“It’s somewhat similar to the way we started February,” Thompson said. “We started with the storm door open. We had storms on Feb. 2 and 4 and were expecting more to come, but the third storm broke up and headed north and that was the end.”

The earth is so parched, he said, that there is very little runoff, he said.

“It’s welcome if it even showers,” Thompson added. “But to do any good, we need the first one to get things wet and get the others to start stream flow. And we need a lot more after that to have any impact.”

The National Weather Service joined in Thompson’s hope.

“Let’s hope that this moist scenario pans out, because Los Angeles now stands about 9.5 inches below normal rainfall since July 1, 1990,” the agency’s statement said.

“We are so far below normal rainfall that it will take a series of heavy storms over a three- to four-week period to dent the record dry spell that California is experiencing.”

The storm predicted for today would be Southern California’s first since Jan. 9, when 0.34 of an inch fell at the Civic Center. So far this season, only 1.38 inches of rain has fallen in Los Angeles, 13% of normal.

The downtown high temperature was 69 degrees Tuesday.