'Bomb cyclone' hits northwest United States

A powerful storm, classified as a "bomb cyclone", has slammed the northwest US, bringing hurricane-force winds and torrential rainfall.

The weather prediction centre announced risks of excessive rainfall from Tuesday through Friday, as the region faces its strongest atmospheric river of the season.

The system has been classified as a "bomb cyclone" due to its rapid intensification.

According to Richard Bann, a national weather service meteorologist, the most severe rainfall is expected between Portland, Oregon, and the northern San Francisco area.

He cautioned about flash flooding risks at lower elevations and winter storms at higher altitudes, emphasising the storm's significant impact.

A winter storm watch was issued for the northern Sierra Nevada above 3,500ft (1,066M), where 15in (28cm) of snow was possible over two days. Wind gusts could top 120kmph in mountain areas, forecasters said.