A slow-moving storm is set to drench Northern California on Friday, with Southern California expected to be heavily soaked by Saturday. Local authorities are warning of potential flash flooding, rockslides, and mudslides in certain areas. Furthermore, the Sierra and Southern California high country will be blanketed with heavy snowfall, posing challenges for travelers.

Prior to the arrival of the Easter holiday weekend storm, a weaker Pacific cold front will sweep through Northern California and the northern Sierra on Thursday, bringing with it modest rainfall and up to a foot of snow. However, compared to the subsequent storm, this system is not predicted to have significant effects other than snow-covered roads and potentially slippery conditions in the Sierra.

The main storm will make its impact felt on Friday, when heavy rain, potentially reaching downpours, will spread across Northern California. Simultaneously, the Sierra will experience heavy snowfall. By Friday night, the rain will extend into parts of Southern California. On Saturday, both rain and mountain snow will engulf the entire region, while showers continue in Northern California. The effects will linger into Sunday, with more rain, mountain snow showers, and a possibility of thunderstorms in Southern California, whereas precipitation will begin tapering off in Northern California.

Fortunately, this storm is not anticipated to have an atmospheric river, a concentrated flow of moisture, resulting in a moderate event overall. The bulk of the state, including the Napa Valley, the Big Sur coast, and the L.A. Basin, can expect approximately an inch of rainfall. Local foothills in the Sierra and Southern California mountains, along with the coastal ranges, may experience higher amounts. In terms of snowfall, the Sierra is projected to receive 1 to 2 feet of snow, with an emphasis on the southern Sierra. The Southern California mountains above 5,500 feet elevation could also receive between 6 inches and 2 feet of snow, as forecasted by the National Weather Service.

Although flash flooding and mudslides are looming, due to the moderate rainfall, the localized impact is expected to be less severe compared to previous atmospheric river events witnessed this season. Urban areas, particularly the usual trouble spots, are more likely to experience scattered flash flooding. Additionally, minor debris flows and mudslides cannot be ruled out.

Fortunately, major road closures in the Sierra, such as Interstates 80 and U.S. 50, are not anticipated as they were during the earlier blizzard this month. However, travelers should be prepared for snowy conditions throughout the weekend. The National Weather Service has indicated that snow might fall at elevations as low as 4,000 feet in Southern California, potentially impacting the Grapevine (Interstate 5) through Tejon Pass from Saturday night into Sunday night.

As residents and visitors alike brace themselves for the storm's arrival, it is crucial to stay informed and take necessary precautions. Authorities are advising people to monitor weather updates and exercise caution on the roads to ensure their safety during this wet and snowy Easter weekend in California.