Expect El Niño this winter, and probably plenty of rain
This winter is likely to be a moderate-to-severe El Niño season, according to the National Weather Service.
The Mercury News says that an El Niño makes it likelier we’ll have a wet winter:
The El Niño now under way doesn’t guarantee that California will receive drenching winter rains. But the stronger the conditions and the warmer the water, the greater likelihood.
Since 1951, there have been six winters with strong El Niño conditions. In four of them, rainfall between the Bay Area and Bakersfield was at least 140 percent of normal. Some of California’s wettest winters, including 1982-83, when Coyote Creek burst its banks, flooding Alviso under eight feet of water, occurred during those strong El Niño winters.
The Mercury News story is accompanied by a nice chart showing the the rainfall in moderate and severe El Niño years.