Biggest rainfall, significant snow and even an atmospheric river predicted for the Western U.S.


Rain, snow and wind are coming in several rounds to the Western U.S.. The biggest rainfall in at least two years, after nearly a year without rain, is expected to hit California. A series of potent Pacific storms are directed at Northern California this week. The front is likely to bring one to two inches of rainfall to the Valley floor, and three to five feet of snow above 10,000 feet in the Sierra Nevada. The storms could lead to flash floods and dangerous debris flows. A rare category 5 atmospheric river event was predicted for Sunday being called a “bomb cyclone” because of its ferocity. It could be at the intensity level of Hurricane Larry. Atmospheric rivers are a narrow band of concentrated moisture in the atmosphere, cruising more than two miles above the ocean; they can transport as vapor, more than 20 times the water that the Mississippi River does, as a liquid. Late Saturday another area of rain will arrive.


Public and private agencies are aware of that risk and are working with the weather service to pin down exactly when and where the front will hit. The shift to a wet weather pattern comes after historic dryness. The rain will help stop smoldering wildfires and could ease water restrictions on farmers. But these events can wreak havoc on travel producing deadly mudslides and causing catastrophic damage to life and property, the National Oceanic and Atmospheric Administration said. “By the middle of next week, snowfall totals could be substantial enough for some resorts to bump up their opening dates,” wrote the winter storm prediction site. Not only California but Utah, Idaho, Wyoming, and Colorado are all set to get significant snow totals.