High Streamflow AdvisoryISSUED: High Streamflow Advisory – Coast
ISSUED: 1:00 PM November 15, 2019

The River Forecast Centre is issuing a High Streamflow Advisory for the Coast including the:

• North Coast including Prince Rupert, Kitimat, Kemano River and surrounding areas
• Central Coast including the Bella Coola River, Kingcome River, Wannock River and surrounding tributaries
• South Coast including Howe Sound, North Shore, Sunshine Coast, Metro Vancouver and surrounding areas
• North Vancouver Island including Gold River, Zeballos River and tributaries around Port Hardy and Port Alice

An atmospheric river event is expected to impact the British Columbia coast over the weekend, bringing heavy rainfall and warming temperatures. Rainfall forecasts from Environment and Climate Change Canada are indicating the potential for 2-day total precipitation amounts in the 100-150mm range in areas along western and northern Vancouver Island and the Central Coast. Lesser rainfall amounts are forecast on other areas of Vancouver Island, South Coast and North Coast regions. Peak rainfall intensities are currently forecasted for Saturday night, lasting into early Sunday morning.

Current hydrologic modelling is indicating the potential for peak-flows in the 2-year to 5-year return period, focused around areas with the highest forecast rainfall. Ten- to 20-year return periods could be possible for smaller stream systems. River levels are expected to rise through Saturday, with peak levels expected through Sunday and into Monday.
The public is advised to stay clear of the fast-flowing rivers and potentially unstable riverbanks during the period of rapid-rising river levels.
The River Forecast Centre will continue to monitor the conditions and update this advisory as conditions warrant.

BC River Forecast Centre -
Ministry of Forests, Lands, Natural Resource Operations and Rural Development

Levels of Warnings/Advisories:

1. High Streamflow Advisory: River levels are rising or expected to rise rapidly, but that no major flooding is expected. Minor flooding in low-lying areas is possible. This is the lowest level.
2. Flood Watch: River levels are rising and will approach or may exceed bankfull. Flooding of areas adjacent to affected rivers may occur. This is the intermediate level.
3. Flood Warning: River levels have exceeded bankfull or will exceed bankfull imminently, and that flooding of areas adjacent to the rivers affected will result. This is the highest level.

Links:

1. Home of River Forecast Centre
2. Current Streamflow Conditions and Flood Forecast Modeling
3. Map of Current Streamflow Return Periods for All WSC Stations
4. CLEVER Model 10-day Forecasts of Discharges and Return Periods
5. COFFEE Model 5-day Forecasts of Discharges and Return Periods
6. Back to page of Flood Warnings and Advisories