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. There are evacuation orders in place for thousands of people in the US and Canada, and authorities have that warned more rain is on the way on Thursday.

In the US, the governor of Washington state, Bob Ferguson, declared a statewide emergency on Wednesday and estimated 100,000 residents could soon face evacuation orders. The emergency declaration warned that continued rain and snow at mountain elevations would exacerbate flooding conditions. Supply chains and transportation could be severely impacted, the declaration added.

Skagit County, a major agricultural area north of Seattle, has issued an immediate evacuation order to residents who live on the floodplain. Some 75,000 people would be evacuated from low-lying areas on Skagit River, the director of the Washington Military Department's Emergency Management Division, Robert Ezelle, told reporters on Wednesday. Snohomish County Sheriff's Office said in an overnight social media post that they had rescued "multiple" people by helicopter after they became trapped in their homes in Sultan, Washington, a community roughly 40 miles (65km) northeast of Seattle.

The sheriff's office warned residents on Thursday morning that the eastern region of the county is most affected after the Skykomish River crested above 24ft (7m) overnight - just shy of a record. (BBC)