Bomb cyclone to slam western states with winds up to 70mph and two feet of snow

A powerful bomb cyclone is set to blast the West Coast with 70 mph winds and up to two feet of snow, causing havoc for travelers.

The storm is associated with an atmospheric river – a long plume of moisture in the sky – taking aim at California and the Pacific Northwest that will drench the area by Wednesday.

The National Weather Service said that a cold front pushing across the region on Monday would allow for unsettled weather ahead of the powerful storm system that would develop on Tuesday. Sub-freezing temperatures were possible Tuesday morning in the San Francisco Bay Area, and a freeze warning was in place for Monday night.

Northern California and Oregon could see wind gusts up to gusts up to 70 mph. Washington will also feel whipping winds that have the potential to knock over trees and cause power outages.

Heavy snowfall of over two feet is possible from the Cascades to the northern California mountain ranges.

Moderate-to-heavy snow is forecast across the Cascade Mountains and northern Rockies, which have already seen multiple rounds of snow this month. Numerous winter storm warnings and advisories were in place across western states on Monday.

By Tuesday, the low pressure system will help to generate high winds across the Pacific Northwest and increase precipitation intensity. By mid-week, the atmospheric river storm will produce four to seven inches of rain from northern California to southwest Oregon.

This could lead to river flooding and an increased risk of mudslides.

The seven-day forecast for the continental US. The National Weather Service says seven to 15 inches of precipitationis expected across northern California and far southwestern Oregon, including rain and snow. (NWS Weather Prediction Center/X)

But, hazards are expected to continue after Wednesday. Media forecasting company AccuWeather said related impacts are anticipated through the end of the week.

The company said the storm has the potential to affect travel on the roads and in the air for the Northwest.

“The same midweek storm has the potential to soak the San Francisco Bay Area with perhaps the biggest rain of the season so far, depending if rain can settle farther south toward the end of this week,” AccuWeather Senior Meteorologist Heather Zehr said in a statement.

A bomb cyclone, known technically as bombogenesis, occurs when a storm’s central pressure drops by at least 24 millibars within 24 hours.