“Monster Storm Hits West Coast: Bomb Cyclone, Life-Threatening Flooding, and More!”
The first major atmospheric river storm of the season has hit the West Coast with a bang, rapidly strengthening into a bomb cyclone before unleashing dangerous winds and heavy rains on Northern California and southern Oregon. The storm, fueled by bombogenesis and warm Pacific temperatures, has the potential to cause life-threatening flooding, high surf, and significant mountain snow.
According to the National Weather Service’s Weather Prediction Center, the storm could bring as much as 12 to 16 inches of rainfall, leading to flash flooding, rock slides, and debris flows. Widespread power outages and tree damage have already been reported in the region, with blizzard conditions expected in the Cascades.
The worst of the winds are predicted to hit Northern California on Wednesday, with more than a foot of rain expected in the North Bay by the end of the week. A flood watch remains in effect through Friday, with a second low-pressure storm system expected to bring additional precipitation.
While the significant rainfall is expected to help Northern California exit fire season, concerns remain about the potential for too much rain too quickly. Forecasters are uncertain about what the storm could indicate for the rest of California’s rainy season, with predictions for above-average rainfall through the end of the month but less clear forecasts for mid-December.
The El Niño-Southern Oscillation cycle remains in neutral, with the possibility of a weak La Niña developing by the end of December. Historically, weak La Niña years have seen slightly less rain than normal, but the influence of a weaker cycle may be minimized.
Water officials are optimistic about the storm’s benefits for California’s snowpack later in the spring and summer of 2025. The rainfall is expected to wet the soils in the mountains, ensuring that snowmelt results in runoff rather than being lost to the soils.
A flood watch remains in effect across the North Bay, with additional rainfall expected in Mendocino and Lake counties and parts of the Sacramento Valley. Mountains in Northern California could see up to 20 inches of snow, with some areas receiving up to 4 feet. In Southern California, forecasters are confident that the region will see measurable rainfall this weekend and into early next week.
Overall, the storm is expected to bring much-needed relief to California’s dry conditions, but concerns remain about the potential for excessive rainfall and the long-term outlook for the state’s rainy season.