A strong, early-season winter storm will dump as much as 3 feet of snow in the high-elevation parts of California's Sierra Nevada mountains this week, which could eventually supplement the water levels of many reservoirs in the area.

Newsweek reached out to the California Department of Water Resources (DWR) by email for comment.

National Weather Service (NWS) meteorologists warned of the storm's approach late last week. The storm will dump several feet of snow in high-elevation areas across Central California through Wednesday night. The heavy snowstorm comes only weeks after California began its new water year on October 1. Heavy snow during the winter season is vital for the health of the state's reservoirs, as 30 percent of California's water supply comes from snowpack.

NWS offices in Hanford and Sacramento have issued a winter storm warning regarding the incoming snowfall.

As of Monday morning, most major reservoirs in California were performing above average for this time of year, according to a graphic from the California DWR. For example, Lake Shasta, the state's largest reservoir, was 109 percent of its average capacity for this time of year. Many other reservoirs were also more than 100 percent of their average capacity for this time of year, including New Bullards Bar Reservoir, Lake Oroville, San Luis Reservoir, Camanche Reservoir, and others.

These reservoirs will unlikely see significant water level jumps immediately after the snowstorm. However, the snowfall will add to the overall Sierra Nevada snowpack. Come spring, when the snow melts, the run-off will make its way to the reservoirs, many of which will then see their levels rise.

Although most reservoirs are performing well for this time of year, the DWR recently warned that California "must be prepared for extreme weather events of all kinds."

"The past decade has clearly demonstrated the need to prepare for extremes," State Climatologist Dr. Michael Anderson said in a DWR news release. "A dramatic flood year in 2023 was followed by two years with large spatial disparities. While our water supplies are in a good position heading into the new water year, we will be watching closely for dry and wet extreme conditions that can pose hazards statewide."

The biggest threat with the incoming storm will be to travel, as falling and blowing snow will limit visibility and roads could become slick.

"Persons should delay all travel if possible," NWS Hanford said in a winter storm warning. "If travel is absolutely necessary, drive with caution and be prepared for sudden changes in conditions. Leave plenty of room between you and the motorist ahead of you, and allow extra time to reach your destination. Avoid sudden braking or acceleration, and be especially cautious on hills or when making turns. Make sure your car is winterized and in good working order."

DWR Director Karla Nemeth, in a news release: "There is no such thing as a normal water year in California. Just in the past two winters, deceptively average rain and snowfall totals statewide masked the extremely dry conditions in Southern California that contributed to devastating fires as well as flood events across the state from powerful atmospheric river events. California must be ready to respond to emergencies from droughts to floods to fires."

NWS Sacramento in a winter storm warning: "Snow levels will be 5500 to 6500 feet, decreasing after Monday night to 5000 to 6000 feet with heaviest snow accumulation expected Monday afternoon to late evening. Snow accumulations may be affected by diurnal trends and sun angle."

The warning added: "Plan for slippery road conditions. Hazardous road conditions are expected to impact the Monday and Tuesday commutes."

Winter storm warnings across central California will remain in place through Wednesday evening. The heaviest snow will fall on Monday afternoon and evening.

How California water levels will change after 3 feet of snow