California slammed by Pineapple Express causing flooding rain, heavy snow, fierce winds

The weather across the Pacific Coast is roaring back to life as a potent storm system spins off the coast, bringing in a powerful Pineapple Express atmospheric river. 

The storm is threatening a myriad of impacts, including flash flooding, damaging winds, power outages and possible landslides. 

A Pineapple Express is a weather pattern that brings a lot of moisture from the tropical Pacific near Hawaii and hits the West Coast hard.

This weather pattern can carry up to 27 times more water than the Mississippi River, and usually features several inches of rain.

“The Pacific Northwest has gotten the brunt of the wet weather over the last couple of days,” FOX Weather Meteorologist Jane Minar said.

“Now, that finally shifts down the coast. So not only are we talking rain though, but we also have wind alerts that are up for the West Coast, especially for the mountains.”

Gusts reached 55-70 mph along some elevated locations across Northern California, including a 70 mph gust along Pine Mountain Fire Road just north of San Francisco in Marin County at 1,700 feet.

And a tree south of San Jose, in the Saratoga community, fell during high winds, injuring a child.

Firefighters said the child was fortunate to just see minor injuries, and the situation could have unfolded much differently.

Strong winds may reach 60-70 mph along the southern Oregon and northern California coasts, with higher gusts in the mountains.

Gusts could also reach 50-55 mph along the coastal areas of the San Francisco Bay area, with widespread gusts of 45-50 mph likely across a wide portion of Northern California. 

High Wind Warnings have been issued there as a result. These winds can potentially down trees, leading to power outages. They will also lead to numerous delays at San Francisco International Airport.

Flood Watches cover much of coastal Northern and Central California, including the San Francisco Bay Area, through Friday morning as the heavy rain is expected to lead to flooded streets and small streams. Larger rivers may overtop their banks, leading to minor flooding as well. 

The progressive nature of the rain, which will move south relatively quickly, will be a limiting factor to a more significant flood risk with this storm, the FOX Forecast Center said.

Rainfall amounts in Northern California are expected to reach 2-3 inches, including the San Francisco Bay Area. The coastal ranges may see as much as 4-6 inches of rain. 

Feet of snow forecast for the Sierra Nevada

Heavy snow will begin Wednesday in the Sierra. Travel will be difficult and impossible because of snow-covered roads and reduced visibility at times, with possible chain controls and road closures. 

Snow may fall up to 2 inches per hour. Up to 4 feet of snow will fall at the highest elevations, and snow could accumulate down to 3,500 feet, the FOX Forecast Center said. This will help a meager snowpack which sits at just 50% of the average, but it won’t fully erase the snow deficit. 

Snow will also be a factor in the mountains of southern California. The cold nature of the system will allow snow levels to drop below 4,000 feet, the FOX Forecast Center adds.

Those traveling along I-5 through the Grapevine region will need to take it slowly as snow levels will drop below 4,000 feet.

At the coast, large powerful waves are expected to batter the coast from Oregon down through Southern California. High Surf Advisories are in effect for large waves, which could tear up popular beaches.

The National Weather Service (NWS) said surf heights for the Southern Oregon Coast through the San Francisco Coast will range from 22-26 feet. Los Angeles beaches are forecast to have 8-12 feet surf, and San Diego beaches will have 10 feet surf.

Pineapple Express moves into Los Angeles area on Thursday

The storm is forecast to move into Southern California and the Los Angeles areas on Thursday, likely leading to slowdowns during the morning commute. 

The lowlands are expected to receive 1-2 inches of rain, while the mountains and surrounding hills may see 2-5 inches. The rain is expected to cause flooding, leading to road closures and debris on mountain and canyon roads.

Especially vulnerable will be those across the San Diego metro area, which was recently impacted by the damaging flooding last Monday. 

The City of San Diego has already issued evacuation notices for the same neighborhoods that saw flash flooding last week.

The NWS has warned of an increased risk of landslides in Western Washington due to heavy rainfall.

Two landslides have already occurred – one in Seattle and the other in the Olympic Mountain foothills.

The main storm system will move overhead by late Thursday.

As a result, the widespread rain will be replaced with scattered showers and even a few thunderstorms, which will linger through Friday.

Second storm for Southern California has potential for greater flooding impacts

However, the stormy pattern won’t end there. Another possibly more impactful storm is forecast to slam into Southern California starting late over the weekend.

“(This storm) has a growing potential for damaging flooding and is the one of most concern (this week),” the NWS in Los Angeles wrote. 

The FOX Forecast Center said initial forecasts show this slow-moving storm has the potential to bring several days of heavy rains to the region.  

More widespread flooding and even heavier mountain snow are becoming increasingly likely.