New Atmospheric River Will Affect The Mother Lode

Photo by: Tracey Petersen

An Atmospheric River event will bring moderate to heavy rain to the region.

The prolonged period of rain will bring the risk of flooding. A Flood Watch has been issued for the Mother Lode, Mariposa County, the Yosemite National Park Valley floor, and the northern Sierra Nevada below 4,000 feet, from this evening through Monday afternoon.

Flooding caused by excessive rainfall is forecast. Excessive runoff will result in rises along area rivers, creeks streams and other low-lying and flood-prone locations. Small streams and creeks may rise out of their banks. Flooding may occur in poor drainage, and urban areas. Mudslides and rockslides may occur in mountain and foothill areas.

You should monitor later forecasts and be alert for possible Flood Warnings. Those living in areas prone to flooding should be prepared to take action should flooding develop.

The National Weather Service has also issued a Winter Storm Warning for the western slope of the northern Sierra Nevada, from 10 PM this evening until 4 PM Monday afternoon. Additionally, a Winter Storm Warning has been issued for Yosemite National Park, above the Valley floor, from 1 AM Saturday until 10 AM Monday.

Heavy snow is forecast above 5,000 feet. The heaviest snow is expected on Sunday.

The snow levels will range from 6,500 to 7,500 feet tonight into Saturday morning. That will lower down to 5,000 to 6,000 feet from Saturday afternoon into Sunday. before finally dropping down to around 4,500 to 5,500 feet by early Monday morning.

Total snow accumulations above the 5,000 foot elevation, will range from one to two feet. Two to five feet of total snow accumulation, is likely above 6,000 feet. The higher you go, the more the snow.

Winds may gust as high as forty-five to fifty-five mph. Such strong winds could cause tree damage and bring down tree branches.

Roads, and especially bridges and overpasses, will likely become slick and hazardous. Travel could be very difficult to impossible. If you must travel above 5,000 feet, keep an extra flashlight, food, and water in your vehicle in case of an emergency. Try to delay all travel if possible. If travel is absolutely necessary, drive with extreme caution and be prepared for sudden changes in visibility. 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 is in good working order.