Authorities issued evacuation warnings and closed coastal roads and beaches Friday as forecasters said monumental waves were taking aim at California’s Northern and Central coasts.

In Santa Cruz County, residents in the area of Las Olas Drive and Beach Drive, and Pot Belly Beach Road, were “strongly encouraged to consider evacuating until conditions have improved,” the Sheriff’s Office said.

The National Weather Service issued a High Surf Warning calling for breaking waves of 25 to 35 feet, occasionally stretching to 40 to 50 feet.

Waves reached 34.1 feet — about the height of a three-story building — at a buoy west of San Francisco on Friday afternoon, the National Weather Service said. Passing the buoy about every 19 seconds, the waves were expected to arrive overnight, forecasters said.

“Large waves have the potential to reach coastal homes and properties, causing dangerous flooding and making access to affected areas difficult or unsafe,” the Santa Cruz County Sheriff’s Office said.

Roads and beaches along the Monterey Peninsula were closed Friday through Sunday morning “with a very likely extension through Tuesday,” the Monterey City Manager’s Office said.

Beach closures included Monterey’s San Carlos and McAbee beach, Pacific Grove’s coastal turnouts, Pebble Beach’s beaches and coastal turnouts, Carmel River State Beach, Big Sur’s Garrapata Beach, Point Lobos State Natural Reserve and Asilomar State Beach.

State Highway 1 was closed near Monastery Beach. In Pebble Beach, 17 Mile Drive was closed to visitors and in some places to residents.

Santa Cruz County deputies said emergency response may be delayed or unavailable if waves reach homes, impact roadways, or otherwise restrict emergency access.

“Residents should not wait for conditions to worsen before considering leaving,” the Sheriff’s Office said.

The Weather Service said people should stay off beaches Saturday. Authorities in Monterey urged the public to avoid coastal cliffs, rocky shorelines, and oceanfront recreational trails.