In a significant development for the region, Northern California and the Pacific Northwest are bracing for a powerful cyclonic storm. The weather office has predicted heavy rains and winds for the region, which is likely to cause power outages and flash floods. The Weather Prediction Center issued excessive rainfall risks beginning on Tuesday and lasting through Friday as the strongest atmospheric river -- long plumes of moisture stretching far over the Pacific Ocean -- that California and the Pacific Northwest has seen this season bears down on the region.
The storm system has intensified so quickly that it is considered a "bomb cyclone", explained Richard Bann, a meteorologist with the National Weather Service Weather Prediction Center.
The areas that could see particularly severe rainfall as the large plume of moisture heads toward land will likely stretch from the south of Portland, Oregon, to the north of the San Francisco area, he explained.
"Be aware of the risk of flash flooding at lower elevations and winter storms at higher elevations. This is going to be an impactful event," he said. In northern California, flood and high wind watches go into effect on Tuesday, with up to eight inches of rain predicted for parts of the San Francisco Bay Area, North Coast and Sacramento Valley.
A winter storm watch was issued for the northern Sierra Nevada above 3,500 feet, where 15 inches of snow was possible over two days.
Wind gusts could top 120 kilometres per hour in the mountain areas, forecasters said. "Numerous flash floods, hazardous travel, power outages and tree damage can be expected as the storm reaches max intensity" on Wednesday, the Weather Prediction Center warned.
In northern California's Yolo County, crews spent Monday clearing culverts, sewers and drainage ditches to avoid clogs that could lead to street flooding. Mesena Pimentel said she hopes the efforts prevent a repeat of floods last February that inundated her property near Woodland.
"We had about ten inches of water in our garage, had a couple gophers swimming around," Pimentel told KCRA-TV. Woodland city officials have set up two locations where residents can pick up free sandbags Authorities urged people to stock up on food and charge phones and electronics in case power goes out and roads become unpassable.
Meanwhile, southern California this week will see dry conditions amid gusty Santa Ana winds that could raise the risk of wildfires in areas where crews are still mopping up a major blaze that destroyed 240 structures.
The Mountain Fire, which erupted November 6 in Ventura County northwest of Los Angeles, was about 98 per cent contained on Monday. Winds will calm by the end of the week, when rain is possible for the greater Los Angeles area.
(With Inputs From PTI)
