Unprecedented Bomb Cyclone Set to Impact the US Northwest This Week

Authorities warn of a major weather event as a bomb cyclone approaches the US northwest, threatening severe conditions including heavy rainfall, strong winds, and significant snowfall for residents across the region.

A "bomb cyclone" is developing off the US northwest coast, poised to affect millions of residents from California to Washington. The storm, expected to reach its peak intensity by the week's end, is forecast to unleash wind, rain, and snowfall, impacting over seven million people along the Pacific coastline. According to the National Oceanic and Atmospheric Administration (NOAA), initial effects of the storm commenced Tuesday and are predicted to escalate throughout the week.

The bomb cyclone is a phenomenon characterized by a rapid drop in atmospheric pressure, leading to extreme weather. The previously experienced bomb cyclone in California in March 2023 serves as a reminder of the potential severity of such storms. Already, regions like Seattle are encountering gusty winds, and NOAA expects heavy snow to blanket mountain ranges in the Pacific Northwest, with rates of up to 3 inches (8 cm) per hour and gusts reaching 65 mph (29 mps).

Travel conditions are anticipated to deteriorate rapidly, resulting in difficult or hazardous travels, while snow accumulations may reach 20 inches (50 cm) in certain locations. Power outages and coastal surf hazards are also a concern, as NOAA issued a "high risk" excessive rainfall outlook for northern California and southwestern Oregon.

Winter weather alerts remain in effect across several areas on the Pacific coast, where officials predict significant flash floods, power outages, and even tree damage as the storm progresses. NOAA describes a bomb cyclone not only by its rapid pressure drop (at least 24 millibars in a day) but also by its capability to spawn a variety of severe weather phenomena from blizzards to intense thunderstorms.

BBC Weather forecaster Helen Rossington notes that the northwest coast will experience strong winds and rain before transitioning into extended periods of heavy precipitation and flood risks. This cyclone is part of a broader pattern of atmospheric river events that have impacted North America in recent weeks. As residents brace for the impending storm, vigilance and preparedness will be key across the affected states.