Californians are getting used to seeing ''the shape of things to come'' on the nightly television news - during the weather segment. Satellite images show storm systems, like huge, white boomerangs, moving in from the western Pacific.
Queens and commuters, presidents and just plain residents find their plans and routines upset by what Californians are apt torefer to as ''Oregon and Washington weather.'' Queen Elizabeth II and President Reagan were unable to meet as planned at the Reagan ranch in the mountains near Santa Barbara because of flooded roads.
Commuters were delayed or turned back by flooded roadways, especially in the San Francisco Bay area, as the latest in a series of winter storms hit the coast Monday. Some residents were forced to abandon homes that were sliding off hillsides or undermined by pounding surf. At least seven deaths were attributed to the storm.
It's the second year in a row for unusually wet, stormy weather in California. Nothing this season has matched the damage wreaked by the storm that hit in the first week of January 1982. But this winter's succession of soggy weather systems, which began in late December, has been costly. A dozen of the state's counties already have been declared disaster areas by Gov. George Deukmejian and President Reagan. Damage in January was estimated by the California Office of Emergency Services at some $100 million.
San Francisco's precipitation records tell the story: 25.22 inches of rainfall to date, according to the National Weather Service, in a ''season'' that begins July 1 and ends the following June 30. ''Normal'' to date would be 15.45 inches. Last year to date, the figure was 25.84 inches. The seasonal normal is 20.66 inches - surpassed before the end of January in the last two years.
But what is normal? Douglas Inman, a scientist at the Scripps Institution of Oceanography in La Jolla, Calif., says conditions of the last two winters should be considered normal. In the view of Dr. Inman, who has spent 15 years studying the state's coastal conditions, Californians have been lulled into complacency by abnormally mild weather over the past three decades, and have built homes and businesses too close to the shoreline.
Much has been made in recent weeks of the damage to beachfront residences and businesses caused by erosion during the Pacific storms. Inman and others point out that damming of California rivers has reduced the amount of sand the streams normally would supply to the beaches.
National Weather Service sources were not ready to comment on the normality or abnormality of recent storm patterns. What they do point out is that the southern jet stream - a high-altitude west-to-east current that steers weather systems across the continent - has been pushing more storms ashore in California in the last two years than for many previous seasons.
Meanwhile, a lot of San Francisco Bay Area residents were upset about one effect of the weather front that hit Monday evening: the high winds knocked out power to many homes just when people were set to watch the 2 1/2-hour finale of M*A*S*H.