Residents in the Pacific Northwest of the US and Canada are bracing for what could be record setting floods as an atmospheric river dumps heavy rain on already swollen rivers.

The US National Weather Service warns that catastrophic flooding is possible in the states of Oregon and Washington along the Skagit and Snohomish rivers.

In Canada, major highways to Vancouver have been closed because of flooding, debris, and the risk of avalanches.

Evacuation orders are in place for thousands of people in both countries, with authorities warning of more rain expected on Thursday.

In the US, the governor of Washington state, Bob Ferguson, declared a statewide emergency on Wednesday, estimating that 100,000 residents could face evacuation orders.

The emergency declaration indicated that continuous rain and snow at higher elevations could worsen flooding conditions, significantly impacting supply chains and transportation.

Skagit County, a key agricultural area north of Seattle, has delivered an immediate evacuation order for residents residing on the floodplain, with around 75,000 people expected to leave low-lying areas along the Skagit River.

In British Columbia, Canada, evacuation orders have been issued for communities like Tulameen and Eastgate, with urgent evacuations affecting 371 properties in the City of Abbotsford.

The region, affected by torrential rain from an atmospheric river, is predicted to receive more storms, necessitating continuous monitoring and preparedness for residents as conditions evolve.