A bomb cyclone hitting Northern California and the Pacific Northwest with heavy rain and high winds has already been blamed for two deaths and is likely to cause flooding, rockslides, debris flows and power outages, the National Weather Service warned Thursday.

And more bad weather is on its way.

The first storm was forecast to last into the weekend and bring another 6 to 12 inches of rain, the weather service said. An atmospheric river prompted a high-risk warning for excessive rainfall along the Northern California coast.

More than 260,000 homes and businesses were without power in Washington state and another 18,000 in California as of 4 p.m. Thursday. In Oregon, winds gusts reached up to 80 miles per hour and parts of Northern California received more than a foot of rain, AccuWeather reported.

Dave Houk, senior meteorologist at AccuWeather, said areas already hit by several inches of rain will see more.

“It will rain heavily for several hours, and that stream of heavy rain will be aimed directly at Northern California before it starts to soften on Friday,” Houk told USA TODAY.

A developing storm system expected to swing along the Oregon and Washington coasts Friday will increase weather conditions in the region, Houk said. But it shouldn’t be as raging as the first, which saw winds of more than 75 miles per hour whip across parts of the state, downing trees and power lines. The coast could see winds of 50 miles per hour or more, but Seattle should be relatively safe with winds of 25 to 25 miles per hour, Houk said.

Still, some power outages and damage are possible, he said.

“This one won’t be as strong and won’t get stronger as quickly,” Houk said. “Hopefully it won’t be what we’ve seen in the last few days.”

Winter weather risks: Winter can bring blizzards, nor’easters and bomb cyclones: what you need to know

Developments:

∎ More than 550 flights to and from San Francisco International Airport were canceled or delayed as of 4:00 PM PT on Thursday. The airport had more than 500 cancellations and delays on Tuesday.

∎ Up to 18 inches of snow is possible for the Washington Cascades, which had already been hit with more than a foot of snow. The storm could also bring several inches to the mountain ranges of western Montana, Idaho and northwestern Wyoming through early Sunday.

Bomb Cyclone Strikes: Two dead, widespread power outages in Washington

Avalanche Warnings, Flood Advisories in Northern California

Numerous roads were closed and vehicles on I-5 north of Redding were screened for tire chains Thursday morning as Northern California grappled with the impact of the powerful storm. Redding, population 93,000, had received nearly 6 inches of rain since the storm began.

An avalanche warning has been issued for Mount Shasta in the Southern Cascades and other parts of Siskiyou County, where heavy snow is expected to be followed by rain.

In the coastal city of Eureka, the National Weather Service office said the Eel River is on track to reach “major flood stage” at 25 feet on Friday. Wind gusts in the area could reach 120 km per hour on Thursday evening.

Farther south, a big rig crashed into the Bay Bridge connecting San Francisco to Oakland early Thursday in the rain, blocking four of five lanes and snarling traffic for hours. A the all-clear was given around 9 o’clock

Flash flood warnings will remain in effect for Bay Area counties north of San Francisco until early Saturday, the weather service said. The Santa Rosa area of ​​Sonoma County has received nearly 12 inches of rain, leading to increasing reports of flooded roads.

Contributions: Rescue Record Searchlight

Storm turns house into ‘fixer-upper’

Nancy Dienes winced as a tall Douglas fir fell onto the roof of the Seattle home that Dienes and her wife, Tracy Matthews, had renovated in recent years. The couple did most of the work themselves.

“When we bought it, it was a fixer-upper,” Dienes told KOMO-TV. “And it feels a bit like a fixer-upper again. We already said we were going to rebuild it.”

New York and New Jersey get a reprieve from the drought

The New Jersey Forest Fire Service lifted fire restrictions Thursday after the drought-stricken state finally got a good soaking overnight, easing concerns about the spread of wildfires during an extremely dry fall. New Jersey recently experienced its driest October on record, lasting into November, leaving the entire state in severe or extreme drought.

New York City also received its first substantial rainfall in seven weeks, a period that prompted officials to issue the city’s first drought warning since 2002. One to three inches of rain are expected through Friday, easing some concerns but not taking the area out of its own arid zone.

“Not drought relief, but it will help, especially with ongoing fire problems,” the NWS said office in New York City said.

Wildfires, particularly in Manhattan’s Inwood Hill Park and Brooklyn’s Prospect Park, have become a major concern this fall for the city’s fire department, which says it responded to an unprecedented 271 fires in the first two weeks of November has responded.

In addition, New Jersey and New York state crews spent nearly two weeks battling the Jennings Creek Fire at the states’ border, which has burned more than 5,300 acres. It is now largely contained.

Two deaths reported in Washington

A woman was killed Tuesday when a tree fell on a homeless encampment in Lynnwood, north of Seattle, local officials said. A second woman was killed near Seattle when a tree fell on her home, Bellevue city officials said. Two people were injured when a tree fell on their trailer in Maple Valley, southeast of Seattle.

“Trees are falling and falling on homes all across the city,” the Bellevue, Washington, fire department posted on social media as the storm raged. “If you can, get to the lowest floor and stay away from windows. Don’t go outside if you can avoid it. Emergency responders are working hard to respond to weather incidents, but prioritizing the safety of life.”

What is a bomb cyclone?

A bomb cyclone – a powerful cold-season coastal storm so named because of its explosive power – is colloquially known as a winter hurricane. Such storms undergo an intensification process known as bombogenesis, which is a rapid drop in atmospheric pressure, marking the strengthening of the storm, according to the National Oceanic and Atmospheric Administration.

Bombogenesis is said to occur when a storm’s central barometric pressure drops by at least 24 millibars within 24 hours. A millibar is a way to measure pressure. The lower the pressure, the more powerful the storm.

Some of the most intense winter storms to batter the country’s coasts are bomb cyclones.

The word ‘bombogenesis’ is a combination of ‘cyclogenesis’, which describes the formation of a cyclone or storm, and ‘bomb’ because of its explosiveness.

“This can happen when a cold air mass collides with a warm air mass, such as air over warm ocean water,” NOAA said. “The formation of this rapidly strengthening weather system is a process called bombogenesis, which creates a so-called bomb cyclone.”

What is an atmospheric river?

Atmospheric rivers, also called ‘rivers in the sky’, are a major factor in extreme rain and snowfall in the West. They function much like rivers on the surface, but can carry significantly more water than the Mississippi River.

This article originally appeared on USA TODAY: Bomb cyclone updates: Hundreds of thousands without power