Huge swathes of California will be battered by up to four inches of rain and two feet of SNOW for days on end as Golden State is hit by atmospheric river, according to latest weather forecast

California will be lashed by rain and even snow for days next week as the first “atmospheric river storm” of the season hits the state.

Significant rain and snow is forecast for large parts of the West Coast starting on Tuesday and continuing through Friday – with some areas seeing a month’s worth of rain in just a few days.

The storm will be caused by a large Pacific system that is currently churning off the coast of Alaska and will turn towards the coast of California in the coming days.

It is expected to be the first atmospheric river storm of the season, with warnings that conditions will change ‘very drastically and rapidly’.

Atmospheric river storms are California’s signature type of winter storm, transporting moisture directly from the tropical Pacific Ocean to the West Coast.

Atmospheric rivers have long wreaked havoc on the West Coast — California alone was hit by at least a dozen last winter — killing 18 people and destroying infrastructure.

The storms are categorized on a five-point scale, with one meaning a weak storm and five an ‘exceptional’ storm.

At their peak, they can transport an amount of water vapor approximately equal to 7.5 to 15 times the average flow of liquid water at the mouth of the Mississippi River.

Next week’s deluge is forecast to be at least a two on this scale, making it a ‘moderate’ atmospheric river event.

Catastrophic widespread flooding is not expected to occur — as the state saw earlier this year — but some areas could receive more than a month’s worth of rain in just a few days.

KTLA weather anchor Kaj Goldberg warned that “things are going to change very drastically and quickly.”

The storm has the potential to bring up to four inches of rain in the Bay Area and Sacramento Valley — with the heaviest deluge forecast for Wednesday for most of the coastline.

Several feet of snow are expected to fall in the Sierra Nevada Mountains, with up to a foot of snow forecast in some foothills next weekend.

The storm will hit California on Wednesday

In some areas, a month’s worth of rain will fall in just a few days

Skies should clear for most of California by the weekend, but only after significant precipitation

The National Weather Service office in Sacramento is forecasting heavy snowfall by the middle of next week, with more than two feet possible in the highest parts of the mountains.

They said there is “potential for flooding, heavy snow above 2,000 metres, strong southerly winds and high surf.”

Forecasters added that “minor urban flooding and small streams and downed trees or power lines are possible as this system moves through the region.”

Residents have been advised to empty their gutters and avoid flooded roads.

The weather will be fueled by a shift in the jet stream — the flow of fast-moving air that moves storms across the planet — which will dip south and point directly toward California.

It is not expected to be as disastrous as the storms that hit the state last winter and earlier this year.

Parts of downtown Pajaro were flooded after a levee on the Pajaro River in Monterey County broke following another storm on Friday. The latest storm has forced nearly 27,000 people to be evacuated due to the risk of flooding and landslides, and 16 major rivers in the state have burst their banks.

Snow in the Sierra Nevada Mountains after an atmospheric river event in March 2023 in Mammoth Lakes, California

In December, a winter storm shut down mountain highways, toppled trees and triggered flood and avalanche warnings from the Northern California coast to Lake Tahoe.

A month later, a state of emergency was declared after more than ten days of storms resulted in the deaths of fourteen people.

Rivers burst their banks, flooding vehicles and causing massive power outages.

In March, 27,000 people were ordered to evacuate after 16 major rivers in the state burst their banks.

On the Pajaro River, a broken dike flooded farms and roads, flooding the entire city of Pajaro, forcing thousands of residents to flee.