Storm pounds foothills, flooding roads and threatening residents of North Fork, Bass Lake

A powerful Pacific storm drenched the Sierra foothills Tuesday, flooding creeks and streams, overflowing bridges and roadways, and prompting a mandatory evacuation order in North Fork.

A flash flood warning was issued just before noon Tuesday for central Fresno County, central Mariposa County, central Madera County, east-central Merced County, and northwestern Tulare County. The warning was in effect until 2:45 p.m.

Residents in several areas in and around Bass Lake were told to be ready to evacuate. In North Fork, the Madera County Sheriff’s Office issued a mandatory evacuation order about 3:20 p.m. for the Bass Lake Mobile Home Park and the east side of Church Street, an area that was threatened by storm runoff last month.

The National Weather Service said law enforcement officials reported flooded roads due to heavy rain across alerted areas as radar estimated rainfall rates of a quarter to half an inch per hour. Flash flooding was expected, and there were reports of mudslides and rockslides in a number of foothill areas. In addition, Pacific Gas & Electric Co. reported high stream flows below Bass Lake near North Fork.

PG&E said water on the Crane Valley Dam spillway at Bass Lake had reached emergency levels.

“PG&E recommends those going near rivers and streams to be aware of the higher flows and take precautions,” spokesman Denny Boyles said.

When the lake’s level reaches the spillway, Boyles said, and spills move faster than 750 cubic feet per second, the emergency alerts kick in. As of 2 p.m., the water was moving at 800 cubic feet per second.

As the rain fell Tuesday afternoon, crews throughout the Valley stepped in to combat flooding issues.

Officer Kaci Lutz, a spokeswoman for the California Highway Patrol in Oakhurst, said her office was monitoring several minor flood-related situations. The CHP also was keeping an eye on the Fresno River, which was rising near the Highway 41 bridge into Oakhurst.

The National Weather Service in Hanford reported around 2:42 p.m. that an earthen dam on Lewis Forks was in imminent danger of failing. Lewis Fork flows just east of Highway 41 south of Sugar Pine. The service warned that residents downstream of the Cedar Valley neighborhood should be ready to evacuate.

The weather service said about an inch of rain fell in three hours at North Fork. For the 24-hour period ending 4 p.m., 4.18 inches of rain fell at North Fork. At Goat Mountain between North Fork and Bass Lake, 5.6 inches of rain were reported. Nearly 5 inches of rain fell in 12 hours. More than 3 inches of rain was reported in Mariposa, and 2.5 inches at Oakhurst and Pinehurst in Fresno County.

In Yosemite National Park, El Portal Road/Highway 140 closed briefly due to water and debris flowing onto the road. It reopened at 2:30 p.m. Big Oak Flat Road was temporarily closed from Crane Flat to the Foresta Road junction due to a rockslide.

The Madera County Sheriff’s Office warned people to stay away from Road 432 at Angel Falls in Bass Lake, as well as Road 426 and Civic Circle, Hidden Falls Road and Lewis Creek at Shady Lane, and Scenic Drive in Oakhurst due to rising water. Flooding also was reported at Coarsegold Creek. Minor mudslides were being reported along Highway 41, north of Cedar Valley near Cedar Valley Drive in Madera County.

The rain-swollen Fresno River in Oakhurst rose so high it swept away large yurts from High Sierra RV, smashing them into the bridge on Crane Valley Road.

The sheriff’s office issued a pre-evacuation advisory for areas around Bass Lake. An evacuation center was set up at Oakhurst Evangelical Free Church, 50443 Road 427 in Oakhurst (near Yosemite High School).

Boys soccer and basketball games between Washington Union High and Yosemite High at the Oakhurst school were canceled because of the storm.

In Fresno County, Sugarloaf Road just east of Auberry was closed after a bridge reportedly collapsed.

Locations likely to experience flooding included Clovis, the south entrance to Yosemite National Park, Orosi, Orange Cove, East Orosi, Yosemite Lakes, Bootjack, Bonadelle Ranchos-Madera Ranchos, Mariposa, Batterson, Trimmer Springs, Park Ridge, El Portal, Crane Valley Reservoir, Mitchell Meadow, Millerton Lake, North Fork, Chilkoot Meadow, Fish Camp and Catheys Valley.

East of Squaw Valley, Fresno County fire crews reported rescuing someone who was trapped in a vehicle at Mill Creek near Brookside Road, near the community of Miramonte.

The weather service said excessive rainfall over the region will cause mudslides near steep terrain. The mudslides can consist of rock, mud, vegetation and other loose materials. Drivers are warned to turn around when encountering flooded roads.

Previously, the weather service forecast an inch or more of rain on the Valley floor and possibly triple that amount in higher areas as the tempest strikes the region.

Things were expected to get wilder in the High Sierra, where the weather service said 7 inches could drop on Yosemite Valley and 4 to 5 inches on the Sequoia National Park region.

The term “Pineapple Express” means a strong flow of precipitation from waters next to Hawaii to the Pacific Coast. It’s a specific version of the “atmospheric rivers” that have been a hallmark of this winter’s storm season.

Rain is expected to taper off and provide a brief break Wednesday before another storm system moves through on Thursday and Friday. The weekend should see a diminishing chance of rain, the weather service said.

This story was originally published February 7, 2017 at 5:57 AM with the headline "Storm pounds foothills, flooding roads and threatening residents of North Fork, Bass Lake."