A "bomb cyclone" with hurricane-like strength and a chart-topping "atmospheric river" coincided Sunday and are forecast to continue into Monday, unleashing flooding rains, wet snow, strong winds and coastal surf across the western United States.

The massive storm has also caused hundreds of thousands of utility customers to lose power.

A bomb cyclone is a rapidly strengthening storm that increases 24 millibars in 24 hours. Atmospheric rivers are narrow bands of concentrated moisture that cruise more than 2 miles above the ocean and release rain or snow when they hit land.

Recent storms have helped contain some of the nation’s largest wildfires this year. But it remains to be seen if the wet weather will make a dent in the drought that’s plaguing California and the western United States.

California’s climate is hotter and drier now and that means the rain and snow that does fall is more likely to evaporate and less likely to absorb into the soil.

California’s 2021 water year, which ended Sept. 30, was the second driest on record and last year was the fifth driest on record. Some of the state’s most important reservoirs are at record low levels.

AP contributed to this report.