The most recent forecasts show El Niño reaching the "very strong" category, but remaining below the strength of the weather pattern that brought significant precipitation to California in the late 1990s.
Computer models suggest El Niño, a warming of the water off the Pacific coast of South America that influences conditions in California, will reach the "very strong" category. The Climate Prediction Center's Aug. 13 report suggested there is greater than 90-percent chance El Niño will continue through the winter and an 85-percent chance it will last into early spring.
El Niño categories range from weak to very strong. Winter 2014-15 brought a weak El Niño as drought-stricken California entered its fourth year of below-normal precipitation.
But the latest forecast does not guarantee a wet winter for the state because El Niño conditions vary. Since 1950, there have been 22 seasons with an El Niño. Twelve brought above-average rainfall and 10 were below-average.
During the 1997-98 El Niño event, frequent downpours led to flooding and mudslides to California.