High streamflow advisories in place across southern B.C. as heavy rain washes over region

Forecasters are warning of swollen creeks and rivers as heavy rain sweeps over southern British Columbia.

High streamflow advisories have been posted for all of Vancouver Island, the Sunshine Coast, Metro Vancouver, the Fraser Valley and the Similkameen and Okanagan regions further east, warning that the possible rapid rise in rivers poses a risk to public safety.

The River Forecast Centre says streams and rivers in the affected areas are expected to rise into Monday with possible localized flooding.

Environment Canada says a Pacific frontal system washed over Vancouver Island and the South Coast over the weekend, bringing up to 90 millimetres to Haida Gwaii and more than 80 millimetres on Saturna Island.

The weather agency is now warning residents in southeastern B.C., from the Boundary region through the West and East Kootenay regions, to expect as much as 50 millimetres of rain before it eases on Tuesday.

The river forecaster says the smaller, low-elevation creeks and rivers are the most at risk of flash flooding because of the remaining snowpack.

"These rain-on-snow events have a high amount of uncertainty based on rainfall totals, ripeness of the snowpack to melt and the fluctuation of the freezing level,'' the centre says in its advisory.