Mountain Snow, Drenching Rain Eye N. Calif. to N. Rockies
A moisture-riddled Pacific parade of storm systems will deliver feet of mountain snow and very heavy rain from the Golden State to the northern Rocky Front Range through early next week.
An atmospheric river will direct an enormous supply of Pacific moisture with tropical origins into northern parts of the Golden State and much of Oregon into Idaho and Montana until Monday night or early Tuesday. Snow will spread inland, burying the taller peaks above 6,000 to 9,000 feet with 2 to 4-plus feet. Up to a foot of heavy, wet snow may pile up as low as 2,500 feet. Even lower snow levels are likely to develop by Tuesday and Wednesday.
Winter Storm Warnings, Winter Weather Advisories, and Winter Storm Watches remain in effect from central and northern California into the Washington Cascades, as well as for the Wasatch Range to the northern Rocky Front Range in Idaho and Montana. Mount Shasta and South Lake Tahoe, Calif., Park City, Utah, Jackson, Wyo., Bellingham, Wash., and Missoula and Lewiston, Mont., are included.
Travel will be difficult to impossible given gusts exceeding 35 to 55 mph will reduce visibility significantly. These gusts may snap tree limbs, branches, and down trees. Highway 89 near Snowman Summit and Dead Horse Summit in northern California, including Mount Shasta Park, U.S. 89 near Logan Summit in Utah, and Interstate 80 in the Wasatch Range in Utah to Interstate 90 from Lookout Pass to Haugan, Mont., are examples of where travel will be very difficult.
Bad travel, gusty winds, and snow will not be the only headliners dished out as the storm’s warm sector will pack oodles of heavy, potentially flooding rain. Flood Watches are in effect across California’s northern Shasta County and the Sacramento Valley through Sunday evening. Cities such as Stockton, Sacramento, Modesto, and Paradise, Calif., will be soaked by 1 to 3 inches of rainfall. Five to 10 inches will fall below 6,500 feet with 3 to 8 inches likely to pelt the Foothills.
Rain this heavy may trigger urban and flash flooding, especially in low-lying, flood-prone locations. Excess runoff may produce river, stream, and creek flooding. Mud and rockslides will be possible in the foothills and mountains as well.
Unfortunately, the Pacific faucet might not shut off until the latter stages of the first week of February. More valley rain and mountain snow will remain in the forecast through Thursday or Friday.