BC River Forecast Centre- High Streamflow Advisory – Vancouver, Howe Sound, and Sea-to-Sky

There is a High Streamflow Advisory, which means that river levels are rising or expected to rise rapidly, but that no major flooding is expected. Minor flooding in low-lying areas is possible.

Please be extra cautious around rivers and streams at this time.

High Streamflow Advisory- Vancouver Island and South Coast

ISSUED: 10:00AM September 23, 2020

The River Forecast Centre is issuing a High Streamflow Advisory for:
• West Vancouver Island
• North Vancouver Island
• Sunshine Coast
• Howe Sound and Sea-to-Sky including the Lillooet River
• North Shore Mountains
• Metro-Vancouver
• Fraser Valley tributaries including the Chilliwack River

A series of storms is expected to impact the British Columbia coast over the next several days. The first system begins today and will continue into Thursday, with following systems passing again later Friday and into the weekend.

Environment and Climate Change Canada has issued a Special Weather Statement for the region, with forecasted rainfall totals for the first storm in the 25-40mm range for Vancouver Island, with amounts exceeding 100mm over West Vancouver Island, and 30-50mm for the South Coast with higher amounts in the mountains.

These storms will mark a significant shift in streamflow runoff conditions which have been dominated by drier summer patterns for the past several weeks. Rivers are expected to rise rapidly in response to rainfall on Wednesday, with peak flows from the first storm expected late-Wednesday or Thursday, with larger rivers expected to reach peak levels later on Thursday or into Friday. Current hydrologic modelling is indicating the potential for streamflow in the 2-year to 5-year flows in some areas which can lead to localized issues and minor flooding.

Additional storm cycles into the weekend will bring additional periods of high streamflow; advisories will be updated to reflect anticipated conditions as we approach the weekend.

The River Forecast Centre continues to monitor the conditions and will provide updates as conditions warrant.

CLICK HERE to see the current conditions and advisories.

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