An atmospheric river washing over British Columbia this weekend has triggered flooding in some communities across the South Coast. Persistent waves of heavy rainfall, fuelled by a Category 4 atmospheric river, have filled gauges and waterways alike throughout the region.

An atmospheric river battering B.C. brought flooding, road closures, power outages and event cancellations in parts of the province on Saturday, with officials saying transportation challenges would likely be exacerbated by the number of people heading out to vote.

A low-pressure system sweeping into B.C. this weekend will tap into a moisture-laden Category 4 atmospheric river to wring out extensive rainfall across portions of the province.

By Sunday, between 80 and120 millimetres of rain is expected to fall, with the intensity expected to ease Saturday night before a second round of heavy rain on Sunday.

Environment Canada is ramping up rainfall warnings in British Columbia, where Vancouver Island, metro Vancouver and the coastal regions of the province are bracing for major downpours through the weekend.

An atmospheric river weather system has hit much of coastal British Columbia, bringing heavy rain, high winds and the risk of flooding.