Intense storms expected in western US

A series of intense storm systems are expected to bring abundant rainfall and strong winds to the western US this week. According to the National Weather Service (NWS), several inches of precipitation will fall across parts of Washington, Oregon, and California, in coastal areas and foothills in particular. Higher elevations can expect snowfall and strong winds could pose a hazard to high-profile vehicles.

Unsettled weather over the eastern Pacific, fueled by a deep low pressure system offshore is expected to kick in early this week. Rainstorms will likely develop over the Intermountain West while higher mountains will experience snowfall. Coastal regions, extending from the northern California to Washington state can expect strong winds.

According to the NWS, a surface cyclogenesis over the Midwest states will results in numerous showers and rainstorms by the morning of October 26 (local time). Intense thunderstorms are possible to the south of the warm front, which will lift northward to the Ohio Valley while cold rains are in store for Wisconsin and Michigan.

The first storm is expected to over the Pacific Northwest Coast through October 25. The storm will be preceded by a moisture plume that will bring rain and thunderstorms across the Southern California, including Los Angeles to the Rockies.

Short Range Forecast, October 24, 2016. Image credit: NWS/NOAA

Short Range Forecast, October 25, 2016. Image credit: NWS/NOAA

Short Range Forecast, October 26, 2016. Image credit: NWS/NOAA

"Several storms will spin off the northwestern United States coast bringing rounds of rain, heavy at times, from northern California to Washington," said Mike LeSeney, an AccuWeather Senior Meteorologist.

A second system will move up the northern California coast and the Northwest during the night of October 25 and 26 (local time) with some rain expected on October 27, as well. This storm will not be as intense as the first one and rainstorms are expected across the region of Seattle to Portland, Oregon and Crescent City, California.

Northwestern California will experience the strongest rainfall, as between 101.6 and 152.4 mm (4 and 6 inches) of accumulated rain is likely by the middle of the week. Localized flash flooding is likely. Abundant precipitation will fall on October 24 and continue into the night (local time). The area west of the Interstate-5 corridor in Washington and Oregon will experience between 25.4 and 76.2 mm (1 and 3 inches) of rainfall.

"Rainfall will generally be light but still a nuisance for travelers on Monday and Tuesday from Seattle to Portland before steadier rain arrives on Wednesday. Rain totals will generally be an inch or less in these areas," said Kristina Pydynowski, an AccuWeather Senior Meteorologist.

Rain will reach the San Francisco area, as well, although expected amounts of precipitation are much lower than in the region northward the Oregon border.

"Winds will gust between 80.5 and 96.6 km/h (50 and 60 mph) along the coast of Oregon and from northern California to south-central Oregon on Monday into Monday evening," Pydynowski added.

Downed trees and power outages are expected.

The Cascades can expect some snowfall, according to the forecast. 

"Snow levels will drop to 1 828.8 m (6 000 feet) by Monday evening and will even dip to 1 676.4 (5 500 feet) by Tuesday morning. However, most showers will have tapered off by Tuesday morning with the majority of the rain confined to places toward the coast," said Pydynowski.

Snow levels will increase to at least 2 438.4 m (8 000 feet) by the time the second storm sets in.

Featured image: Short Range Forecast, October 25, 2016. Image credit: NWS/NOAA