The River Forecast Centre has issued a flood watch for the North Coast region.
With an intense frontal system passing over the region, heavy rainfall of up to 125 mm Monday and up to 70 mm Tuesday is expected in the Terrace and Kitimat areas.
River levels are expected to respond with rapid rises through Monday evening and throughout the day on Tuesday
Officials say rainfall amounts in this range have caused significant swelling of rivers and localized flooding in the past.
A flood watch means that river levels are rising and will approach or may exceed bankfull and flooding of areas adjacent to affected rivers may occur.