A potent atmospheric river is set to unleash its force upon California through the Christmas holiday, bringing a series of intense weather conditions. Residents across the state should prepare for three distinct waves of heavy rainfall, powerful winds, and substantial snowfall in the mountainous regions. Northern California is anticipated to bear the brunt of the storm, facing a heightened risk of flash floods, debris flows, and extensive river flooding. Some areas could receive the equivalent of a month's worth of rain in just a few days, posing a significant threat to infrastructure and safety.