Californians told to stay away from ocean or face ‘certain death’ after record-breaking storms hit US

National Weather Service warns of towering 50ft waves

US forecasters issued a dramatic warning about the risk of deadly waves after fierce storms lashed both the east and west coasts over the weekend.

A powerful storm system hit California with high surf on Sunday, and meteorologists predicted towering waves of up to 50ft could strike parts of the state’s coastline on Monday.

The National Weather Service told surfers and swimmers that the swell from the Pacific Ocean was the largest “wave event” of the season and posed grave danger.

“Stay well back from the ocean or risk certain death,” the warning stated. The advice remains in place until 9pm local time on Monday.

It follows the death of a surfer at San Francisco’s Ocean Beach earlier this month, when waves reached 10ft.

The latest warning led the World Surf League to cancel “big wave tour” events scheduled for Monday at “the Mavericks” near San Francisco, according to NBC News.

The east coast, meanwhile, was drenched with record rainfall from a storm system sweeping in from the Atlantic Ocean.

On Saturday, daily rainfall records were “easily” broken in Washington DC, Baltimore and at Dulles airport, where almost 2.5in fell, according to the National Weather Service.

Washington DC also surpassed its own annual record for rain. The total observed rainfall for the year reached 61.34in, breaking the city’s previous record of 61.33in set back in 1889.

A coastal flood warning was issued for the shoreline at Washington DC and will stay in place until Tuesday.

Flood warnings for multiple locations in both Baltimore and Washington DC also remained in place on Monday.

The National Weather Service said an El Nino event – a warm ocean current in the Pacific that drives extreme weather patterns – was predicted to form this winter. The phenomenon could bring a higher chance of flooding on both the east and west coast.

In November the UN’s World Meteorological Organisation warned there is a 75 to 80 per cent chance of a weak El Nino forming within the next three months.