A flood watch advisory remains in effect on Monday (Jan. 29) for the Fraser Valley and the Sumas River as wt weather continues to drench the B.C. coast.
The B.C. River Forecast Centre upgraded the advisory for the Sumas River to a flood warning on Sunday (Jan. 28) but downgraded it later in the night.
The Centre says a flood watch means that river levels are rising and will approach or may exceed bankfull, while adjacent areas are prone to flooding.
According to the advisory, a series of storms have delivered 50 to 200 mm of rain through most of coastal B.C. since Friday (Jan. 26) with more expected in the coming days.
“Temperatures are expected to warm during this period, and snowmelt at lower and mid-elevations will provide additional runoff to rivers,” the advisory reads.
High flows on the Nooksack River in Washington have reached local flood stage with the Nooksack River near Cedarville gauge reaching 147.2 ft at 12:30 p.m. Sunday.
“Additional hazards for overflow from the Nooksack may be present from the incoming storm systems on Monday through Thursday, however hydrologic modelling from the Northwest River Forecast Center with the US National Weather Service is not forecasting this scenario,” the advisory says.
Rivers are expected to experience periods of high flows into next week with peak levels in most areas from Monday to Tuesday (Jan. 30).
Meanwhile, Environment Canada added a rainfall warning for Kitimat, saying the community could receive up to 75 millimetres of rain by Tuesday morning.
A wind warning also spans Prince Rupert and Haida Gwaii, where the weather office says gusts could reach speeds of 110 kilometres per hour before easing Monday.
A flood watch remains in effect for Vancouver Island, the Sunshine Coast, the North Shore mountains, Howe Sound, the Sea-to-Sky region and parts of the Fraser Valley.
A lower-level streamflow advisory is also in effect for the Central Coast.
Sunday’s update said rivers with potential for flooding on the island include the Gold, Salmon, Somass, Englishman, Qualicum, Chemainus and Cowichan rivers.
On the mainland, it says rivers with potential for high flows and flooding include the Stawamus, Squamish, Mamquam and Cheakamus rivers, as well as tributaries around the North Shore mountains, the Fraser Valley and the Sunshine Coast.
An Environment Canada bulletin says snowmelt from above-seasonal temperatures is adding to the potential for flooding and landslides throughout the South Coast.
The heaviest rain is expected on Monday, it says, but the rainstorms could last until the middle of the week.
The weather office says the rains combined with mountain snowmelt raises the risk of landslides in “vulnerable areas” as water falls on already-saturated surfaces.
READ MORE: Flood watch expanded as more atmospheric rivers head for B.C.’s south coast
