What is a bomb cyclone? What to know about the storm hitting Pacific Northwest
The Pacific Northwest was pummeled by a bomb cyclone, a severe winter storm that has brought heavy rain and strong winds to the area.
The storm was already blamed for two deaths and will likely fuel flooding, rock slides, debris flows and more power outages, the National Weather Service warned on Thursday.
A woman was killed on 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.
Here's everything to know about bomb cyclones and how the major storm is affecting Oregon and Washington.
What is a bomb cyclone?
A bomb cyclone, which is created through a process known as bombogenesis, is a severe winter storm.
Essentially a "winter hurricane," a bomb cyclone occurs when a storm rapidly intensifies, and its central barometric pressure drops at least 24 millibars in 24 hours. The lower the pressure of a storm, the higher its intensity, the Weather Channel reports.
Many of the most intense winter storms to batter the country's coasts have been bomb cyclones.
Bomb cyclone hits Oregon, Washington, California
The bomb cyclone that hit the area was likely to bring more rain to Oregon, Washington and northern California, even as another storm is expected to hit on Friday.
The first storm was forecast to linger into the weekend and produce an additional 6-12 inches of rainfall, the weather service said. The "atmospheric river" prompted a high-risk warning for excessive rainfall was issued along the northern California coast. More than 330,000 homes and businesses were already without power in Washington state.
Another storm system was expected to hit the area on Friday. The developing storm system was forecast to swing off the Oregon and Washington coastline, adding to the region's weather woes, the weather service said.
"A punch of gusty winds are expected, mainly along coastal regions, could produce rough surf and additional isolated power outages," weather service meteorologist Cody Snell wrote in a storm update early Thursday.
Heavy snow is possible from the Washington Cascades to the western Montana, Idaho, and northwestern Wyoming mountain ranges through early Sunday, Snell said.