Major storms threaten catastrophic floods in northern California and the Northwest
- A storm system is moving into Northern California, bringing rain to the valleys and snow to the Sierra Nevada starting late on December 24, 2024.
- Travel disruptions are expected due to heavy precipitation amounts and flooding concerns along with coastal warnings of high tides.
- These storm patterns are associated with a series of atmospheric rivers, increasing the risk for significant rainfall and potential holiday travel delays.
In Northern California, a series of storms is set to impact the region just before Christmas. On December 24, 2024, a storm system will bring widespread rain to the valleys and snow to the Sierra Nevada mountains. The Sacramento area is expected to experience rain showers starting overnight and continuing through Tuesday afternoon, with isolated thunderstorms likely during the early morning. Precipitation amounts are predicted to reach up to 2 inches in certain valley areas, while foothills may see as much as 4 inches of rainfall. Snowfall is anticipated for elevations above 6,000 feet, with as much as 10 inches possible in some mountain areas, leading to a Winter Weather Advisory for locations above 5,000 feet effective from 7 a.m. to 7 p.m. on December 25. Concerns about flooding have emerged, particularly with a Coastal Flood Warning active for Northern California’s west coast, where wave heights between 30 to 40 feet are expected, putting coastal communities at risk for flooding and high tides. Christmas Day is expected to bring a temporary lull in storm activity, allowing the region to dry out for a brief period, with daytime temperatures reaching into the 50s across valleys and foothills. Nevertheless, another storm is forecasted to approach by Wednesday night, bringing more valley rain and Sierra snow. By Thursday, conditions could worsen again with snow levels dropping to 4,500 feet and creating hazardous travel conditions with potential slick roads and chain controls. This active weather pattern is part of a series of atmospheric river events predicted to continue through the Pacific Northwest and Northern California, heightening flood risks in these regions. The anticipated rainfall could lead to swollen rivers, particularly in populations that have already experienced significant rainfall, increasing the likelihood of flooding incidents. Overall, holiday travel could be disrupted as a result of these ongoing weather challenges, with drivers urged to remain cautious in rapidly changing conditions with storms expected to persist through the weekend and into early January.