Flood Warnings and Advisories

Flood Watch – Howe Sound, Sunshine Coast, North Shore, Fraser Valley (North)
High Streamflow Advisory – Squamish River, Sea-to-Sky, Fraser Valley (South)
ISSUED: 11:00 AM November 25, 2018

The River Forecast Centre is issuing a Flood Watch for the South Coast including:

  • Howe Sound - including the Stawamus River and tributaries along the Sea-to-Sky Highway
  • Sunshine Coast – including watersheds around Gibsons and Sechelt
  • North Shore – including the Seymour River and watersheds around North Vancouver and West Vancouver
  • Fraser Valley (North) – including mountainous tributaries from Coquitlam to Harrison

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

  • Squamish River
  • Sea-to-Sky – including tributary watersheds along the Sea-to-Sky corridor north of Squamish to Whistler
  • Fraser Valley (South) – including the Chilliwack River and surrounding tributaries

A series of intense Pacific storms are expected to impact the South Coast of British Columbia over the next few days. Strong winds and rising temperatures are expected later on Sunday, followed by heavy rainfall throughout Monday and into Tuesday. Current weather modelling is indicating the heaviest rainfall amounts are expected around the Sunshine Coast, Howe Sound, North Shore, and Fraser Valley (North). Environment and Climate Change Canada has issued Special Weather Statements and Rainfall Warnings, and indicate that there is still some uncertainty over rainfall totals for this event. Weather model output is indicating the potential for rainfall accumulations in excess of 100-150 mm over higher terrain, and lesser amounts at lower elevation.
River levels are expected to rise rapidly in response to this rainfall throughout Monday. Shallow snow accumulations at mid-elevations over the past few days is expected to melt with warmer temperatures, and will contribute additional runoff to streams. Hydrologic modelling is indicating the potential for flood conditions to develop, particularly in areas with the highest forecasted rainfall amounts. Peak flows are expected late Monday and into Tuesday. As the storm passes on Monday, there will be increased certainty over rainfall amounts and the locations which have the greatest risk of high flows.
The River Forecast Centre will continue to monitor conditions and update this advisory as conditions warrant.

Contact for Media Relations, Ministry of Forests, Lands, Natural Resource Operations and Rural Development:
Tel: 250 356-7506

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.
  2. Flood Watch: River levels are rising and will approach or may exceed bankfull. Flooding of areas adjacent to affected rivers may occur.
  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.

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