Following the avoidance of a second “bomb cyclone” in the northwest of the United States, the region is now under the influence of an “atmospheric river,” a narrow area in the atmosphere with high concentrations of water vapor. It is forecasted that certain areas will receive rainfall ranging from 6 to 12 inches, potentially leading to flash floods and landslides. The rainfall is expected to persist until this weekend.
According to various media reports, earlier this week, the first round of “bomb cyclone” brought fierce winds that slammed parts of Washington state, resulting in at least two fatalities and power outages affecting over 600,000 households. Social media platforms were flooded with images showing trees toppling onto cars and houses in the affected areas.
The National Weather Service’s Weather Prediction Center initially anticipated a second “bomb cyclone” hitting the region, but the storm’s pressure did not rapidly drop within 24 hours, preventing the formation of a bomb cyclone. However, the Pacific Northwest area was still hit by a new “atmospheric river” storm.
Equivalent to 15 times the amount of water in the Mississippi River, the “atmospheric river” brought strong winds and heavy rainfall to Washington, Oregon, and northern California starting from Thursday (21st). The San Francisco Bay Area experienced the heaviest and most intense rainfall, leading to water accumulation on roadways and disasters like flash floods, landslides, and mudslides in hilly areas. Additionally, higher elevations saw snowfall.
The National Weather Service issued a warning that on Friday, Northern California could experience wind speeds of up to 75 miles per hour, with the possibility of life-threatening floods, mudslides, and landslides in certain areas. According to the National Oceanic and Atmospheric Administration, the rainfall from this “atmospheric river” is set to last throughout the entire weekend.
As of the time of this report, over 125,000 households and businesses in Washington state and Northern California remain without power.