'Bomb cyclone' hits northwestern United States...Two residents died.

A so-called "bomb cyclone" has hit the northwest United States, causing a series of damage.

In Seattle, two residents were killed when a tree broken by hurricane-force winds hit homeless encampments and homes.

In addition, tens of thousands of electricity was cut off in California and Nevada, with more than 500,000 power outages reported in Washington state alone.

Weather officials warned of heavy rainfall of up to 250 millimeters by Friday local time and issued a flood warning for areas north of San Francisco.

In addition, winter storm warnings have been issued in mountainous areas such as the Sierra Nevada, where heavy snow of up to 28cm is predicted.The

'bomb cyclone' occurred as the cyclone strengthened rapidly in a short period of time, and in this case, the formation of a 'atmospheric river' containing huge amounts of water vapor towards the Pacific Ocean strengthened its power.