A storm off the coast of the US northwestern and western Canada is pummelling the region, bringing high winds, flooding, and snow to over seven million residents living in states along the Pacific Ocean. The storm has caused widespread power outages for hundreds of thousands of Americans, and its strong winds have downed trees.

At least one person – a woman near Seattle – has died.

The “bomb cyclone” – as forecasters call it – has been caused by air pressure quickly dropping off the coast, rapidly intensifying the weather system. The storm’s effects were seen on Wednesday morning, with fallen trees damaging homes and blocking roadways in Washington state.

A woman died when a tree fell on a homeless encampment in Lynwood, north of Seattle, Washington, according to a social media post from the South County Fire Department.

High winds are leading to power cuts. On Wednesday morning, more than 600,000 homes in Washington were without power, according to poweroutage.us. Around 15,000 customers were experiencing outages in California.

Several schools in Washington are expected to close or face disruption.

Beyond wind, rain and snow, the storm could also bring flash flooding, rock slides and debris flows, as well as heavy mountain snow, in areas of high elevation. The storm is expected to create blizzard conditions through the Cascade Range of mountains, which runs through both countries.

Winds are expected to subside by midday on Wednesday. But atmospheric moisture around northern California is expected to linger through the week, bringing excessive rainfall.