BC Weather Alerts: Flooding, Snow & Storms Hit Province

Environment Canada has issued a widespread series of weather alerts for British Columbia, warning residents of potential hazards ranging from heavy rainfall and flooding to significant snowfall and strong winds. The alerts, issued beginning Sunday, cover much of the province, from the South Coast to the northern interior, and are primarily linked to an approaching atmospheric river.

The atmospheric river impacting the South Coast, including areas northeast of Metro Vancouver and the North Shore, is forecast to deliver up to 120 millimetres of rain, raising concerns about potential flooding. Environment Canada’s weather alert warns of “extensive water pooling on roads and washouts,” and advises drivers to avoid travelling through flooded areas and to anticipate travel delays. Officials also caution that landslides are possible in vulnerable areas, such as steep slopes or recently burned regions.

Heavy rainfall is also anticipated along the north and west coasts of Vancouver Island, with potential accumulations reaching 150 millimetres, and even exceeding 200 millimetres in certain locations. In response, the B.C. River Forecast Centre upgraded high streamflow advisories to flood watches on Sunday for the northern and western portions of Vancouver Island, as well as the Central Coast. A flood watch signifies potential flooding near riverbanks, while a high streamflow advisory indicates the possibility of minor flooding in low-lying areas.

Winter Storms and Snowfall Warnings

Further north, the Sea-to-Sky region, stretching from Squamish to Whistler, is under a winter storm warning. Up to 20 centimetres of snow is expected by Monday midday, transitioning to periods of heavy rain later in the day and continuing through Wednesday, potentially adding another 70 millimetres of rainfall. Avalanche Canada has issued a “high” avalanche risk warning – the fourth highest level on their five-tier scale – for the Sea-to-Sky region, the South Coast, and most mountain terrain in the north and the Rockies.

In Kitimat and Terrace, snowfall accumulations have already reached up to 40 centimetres since Sunday afternoon, prompting a winter storm warning. Similarly, Bella Coola and Hagensborg on the Central Coast have received 15 centimetres of snow, with forecasts predicting a shift to heavy rain, potentially delivering up to 70 millimetres by Tuesday morning. Environment Canada warns that this rain falling on existing snowpack could lead to localized flooding.

A wind warning is also in effect for the Fraser Canyon, anticipating strong southerly winds associated with a developing low-pressure system. Utility disruptions are possible, and residents are advised to secure any loose objects. Northern B.C., near the Yukon border, could see up to 20 centimetres of snowfall by Monday midday, accompanied by wind gusts up to 50 km/h, reducing visibility.

The northeast region, including areas north and west of Fort Nelson, is expected to receive up to 15 centimetres of snow. The North Coast, encompassing Stewart and Highway 37, could experience up to 40 centimetres of snowfall. Finally, the central Interior and Cariboo regions, including Prince George and Williston, are anticipating snow that will transition to rain showers as temperatures rise throughout the day.

Understanding Atmospheric Rivers

Atmospheric rivers are long, narrow bands of concentrated moisture in the atmosphere. They are responsible for a significant portion of the West Coast’s annual precipitation. While they are a natural phenomenon, they can become particularly hazardous when they stall over an area, delivering prolonged periods of intense rainfall or snowfall. The intensity of an atmospheric river is categorized on a scale from 1 to 5, with a Category 1 being considered weak and a Category 5 being exceptional. The current atmospheric river impacting B.C. Has not been officially categorized, but the anticipated rainfall amounts suggest it is at least a Category 3 event.

Flood Watches vs. High Streamflow Advisories: What’s the Difference?

The B.C. River Forecast Centre uses a tiered system to communicate potential flood risks. A high streamflow advisory means that river levels are rising or are expected to rise, and that minor flooding in low-lying areas is possible. It’s a call for vigilance and preparation. A flood watch, however, indicates that flooding of areas adjacent to riverbanks is expected. What we have is a more serious alert, and residents in affected areas should be prepared to accept action to protect themselves and their property. The upgrade to a flood watch for parts of Vancouver Island signifies a heightened risk of more significant flooding.

What Happens Next?

The atmospheric river is expected to persist over B.C.’s South Coast through Wednesday. Environment Canada will continue to monitor the situation and issue updated weather alerts as needed. Residents in affected areas are encouraged to stay informed about the latest forecasts and warnings, and to take appropriate precautions to protect themselves and their property. The B.C. River Forecast Centre will also continue to monitor river levels and provide updates on flood risks. As the weather system moves through, officials will assess any damage and initiate recovery efforts.

The situation remains dynamic, and further updates will be provided as the atmospheric river progresses. Residents are urged to consult official sources for the most current information and guidance.