The low pressure system that produced the atmospheric river moved into Alberta during the following days leading to the first snowfall of the season in parts of that province.

A strong low pressure system developed in the Gulf of Alaska in the days leading up to the event, pulling a cold front along with it.

[5] The motion of the low stalled the cold front and associated moisture plume with heavy rain being observed in the Lower Mainland and Vancouver Island.

Chinook winds were observed in Alberta while heavy precipitation was falling in British Columbia before the system moved eastward and brought snow to Calgary and Edmonton on October 21.

[10] A couple days before the floods, Environment Canada issued a rainfall warning due to an atmospheric river expected to "drench the B.C.

The British Columbia River Forecast Centre issued flood watches for numerous areas and authorities highlighted the risk of landslides and power outages.

The trajectory of the moisture plume limited the impact of the Olympic Mountain rain shadow in parts of British Columbia.

Flows of muddy water and debris were noted in West Vancouver and TransLink riders encountered detours and delays.

[2] Six homes were evacuated in the District of North Vancouver when heavy rain in Deep Cove overwhelmed the stormwater system.

There were isolated instances of the sewer system overflowing with fourteen reports of raw sewage entering into area waterways.

[27] Washouts along Highway 14 led to that road being closed between Jordan River and Port Renfrew with repair work expected to last until October 23.

Environment Canada meteorologists issued the first snowfall warnings of the season along the British Columbia – Yukon border where 20 cm (7.9 in) of snow was forecast.

[34] High water and damage from strong winds impacted travel in Whatcom County with several road closures.