Rivers swell as wet storm moves through Northern California

Parts of Yosemite National Park remained closed as the Merced River peaked several feet above flood stage through the Yosemite Valley. (Photo by Bernard Spragg. NZ/Flickr, Public Domain)

SAN FRANCISCO — Up to 6 inches (15 centimetres) of rain fell over two days as a drenching “Pineapple Express” storm swelled rivers and flooded roads in Northern California, forecasters said Saturday.

The heaviest rain was in the northern Sierra and in coastal counties from San Francisco north to Mendocino during a 48-hour period beginning Thursday afternoon, the National Weather Service said. Downtown San Francisco saw nearly 2 inches (5 centimetres) on Friday, making for the fourth-wettest April day since record-keeping began.

The storm tapered off by late Saturday morning but minor flooding continued along the swollen Truckee River near Lake Tahoe. Parts of Yosemite National Park remained closed as the Merced River peaked several feet above flood stage through the Yosemite Valley.

No major problems were reported, but runoff from melting snow could add to the chance of rapidly rising streams and rivers, forecasters warned.

The wet weather resulted from a strong “atmospheric river” of subtropical moisture that moved east from Hawaii.

Police rescued a man who became trapped in a rain-swollen drainage channel near Sacramento, where many roads were flooded. The state capital saw more than 1.17 inches (nearly 3 centimetres) of rain on Friday.

Sonoma County officials said there were no major mudslides in areas stripped bare by last fall’s wildfires.

San Francisco International Airport reported about 150 cancelled flights because of the weather and others were delayed.

The opener of the San Francisco Giants-Los Angeles Dodgers weekend series was rained out, the first at the Giants ballpark in 12 years. Saturday’s game was also pushed back by two hours.

To the north, state officials warned this week that they may have to use the partially rebuilt spillway at Oroville Dam for the first time since repairs began on the badly damaged structure last summer.

The water level in Lake Oroville topped 797 feet (243 metres) on Saturday. If it reaches about 830 feet (253 metres), water managers said they may open the gates to the spillway. Officials said they are confident it can safely function.