Fraser Valley/Victoria (Ministry of Water, Land and Resource Stewardship) – Issued: 4:50 PM December 24, 2023
The River Forecast Centre is issuing a High Streamflow Advisory for:
- Vancouver Island
- South Coast including the Sunshine Coast, Howe Sound, North Shore Mountains
- Lower Mainland including the North Shore Mountains, Fraser Valley and surrounding
tributaries
Weather Synopsis:
An atmospheric river is expected to bring moderate to heavy precipitation to coastal British
Columbia beginning on Monday. Current forecasts indicate that the storm will be centered on
western and northern Vancouver Island, with likely spill over into southern and eastern
Vancouver Island. It is possible that heavy precipitation will extend farther inland, up Howe
Sound and across the Lower Mainland.
River Conditions:
River levels are expected to rise quickly beginning on Monday night in areas receiving the brunt
of the storm, with flows likely peaking Tuesday into Wednesday depending on the timing of the
heaviest rainfall and the size and location of affected river systems. Current forecasts suggest
that flows will be highest for North and West Vancouver Island, the North Shore Mountains,
and the Lower Fraser Valley; however, nearby areas may also be affected if higher than
forecasted rainfall occurs.
Uncertainty remains high about the specific storm track and rainfall amounts, as well as the
significance of rain-on-snow inputs. If temperatures are slightly warmer than forecast,
snowmelt and rain-on-snow may provide substantial additional contributions to runoff. Minor
flooding in low-lying areas is possible. Snowmelt and heavy runoff may cause pooling and
localized flooding in areas with poor drainage (i.e., where stream channels and drainage
structures are impacted by snow, ice, or debris).
The River Forecast Centre continues to monitor the conditions and will provide updates as
conditions warrant.
