The River Forecast Centre has upgraded Howe Sound and the Sea to Sky to a flood watch, with heavy rain expected to cause rivers to rise rapidly on Tuesday and Wednesday.
The watch, issued Nov. 9, also covers the North Shore Mountains and other parts of the South Coast. A flood watch means river levels are rising and could reach or exceed their banks, potentially flooding nearby areas.
Following a series of atmospheric rivers last week, another round of storms is expected to reach the B.C. coast on Tuesday, Nov. 10. The centre says the heaviest rain is forecast for Tuesday and Wednesday, with more rain lingering through the rest of the week.
Weather models indicate Howe Sound, the Sea to Sky and the North Shore Mountains could be among the areas receiving the heaviest rainfall. Warm temperatures through Wednesday could also melt shallow snowpacks at higher elevations, adding to runoff.
The centre says river modelling indicates flows could reach levels associated with five- to 10-year events, or higher, in some areas. Uncertainty about where the heaviest rain will fall means those flows are possible throughout the watch region. Smaller rivers and tributaries are particularly vulnerable to sudden increases in flow and rapidly worsening conditions.
Heavy rain and high streamflow increase the risk of unstable banks, erosion, submerged roads, flooding and landslides. Residents are urged to stay away from fast-flowing riverbanks and never drive across flooded roads, bridges or river crossings.
The centre also advises keeping storm drains clear of leaves, which can block drainage. It will continue monitoring conditions and issue updates as needed.
