US, Canada: Adverse weather forecast in northwestern US and southwestern Canada through at least Dec. 2 /update 17

Event

Further snow and rain are likely in the northwestern US and southwestern Canada through at least Dec. 2. Additional rainfall could result in flooding or flash flooding on already saturated soil and exacerbate current disruptions.

Authorities in British Columbia have extended the provincewide state of emergency through at least Dec. 14 due to the continued threat of flooding. Under the state of emergency, security personnel are deployed to assist local authorities with cleanup operations and maintain supply chains. Vancouver has been particularly affected by flooding. Officials closed multiple roads and railways throughout the province due to flooding, including major routes into and out of Vancouver since Nov. 15; most have since been reopened. At least four people have died and one other is still missing due to a mudslide on Highway 99 near Lillooet.

Authorities have issued new evacuation orders in parts of British Columbia. In Abbotsford, evacuation orders and alerts are in place in Sumas Prairie and its vicinity. Emergency shelters are located at TRADEX (Fraser Valley Trade and Exhibition Centre) and Chilliwack Landing Sports Centre. A do not use water notice is in effect for Sumas Prairie. The Thompson-Nicola Regional District has also ordered residents from parts of electoral areas "I" and "N" to evacuate due to flooding, while evacuation alerts are in place for electoral areas "I", "M", and "N". The Frazer Valley Regional District has issued evacuation orders for areas along the Chilliwack and Fraser rivers while evacuation alerts are in place for Hatzic Valley and the Regional District of Okanagan-Similkameen has also issued evacuation orders and alerts to properties along the Similkameen and Tulameen rivers due to flooding.

Operations at the Trans Mountain pipeline have been suspended since Nov. 13 as a precaution. Almost half of British Columbia's gasoline is supplied by Alberta through the Trans Mountain pipeline. Trans Mountain is currently assessing the condition of the pipeline from the air and ground but access is being hampered by debris and damaged transport networks. Authorities stated that they are still days away from restarting the pipeline as of Nov. 29. Parkland Corporation has paused the refinery processing operations at Burnaby due to the lack of crude oil supply from the pipeline. The refinery will be maintained in ready-mode so processing can be resumed quickly once crude oil supply is restored. Authorities are limiting the general public to 30 liters of gas per visit to gas stations in the Lower Mainland-to-Hope region, the Sea-to-Sky region, Sunshine Coast, the Gulf Islands, and Vancouver Island through at least Dec. 14.

Residents in British Columbia Province's border communities are allowed to cross the border into the US for gas and other essential goods, and return without a COVID-19 test or quarantining, whether they are vaccinated or not.

Government Advisories
As of early Dec. 1, the US National Weather Service has issued flood watches and warnings across northwestern Washington.

The Meteorological Service of Canada has issued the following red (the highest level on a three-tier scale) warnings:

• Winter Storm: Banff and Jasper National Parks in Alberta Province with snow of 50-80 cm (20-31 inches) likely along Highway 93 from Jasper and Lake Louise to Saskatchewan River Crossing through early Dec. 2; North Coast in British Columbia Province.

• Freezing Rain: Athabasca, Barrhead, Edson, Evansburg, Fort Saskatchewan, Fox Creek, Mayerthorpe, Morinville, Redwater, Slave Lake, Smoky Lake, Spruce Grove, Swan Hills, Vegreville, Westlock, and Whitecourt in Alberta Province; Big River, Carrot River, Duck Lake, Green Lake, Meadow Lake, Melfort, Nipawin, Pierceland, Prince Albert, Shellbrook, Spiritwood, and Tisdale in Saskatchewan Province.

• Snowfall: Fort Vermilion, Forestry Trunk Road Highway 734, High Level, Mackenzie Highway, Nordegg, and Rainbow Lake in Alberta Province; Chilcotin, Fort Nelson, Kinbasket, Watson Lake, and Yellowhead in British Columbia Province; Watson Lake in Yukon Territory.

• Rainfall: Central Coast, Elk Valley, Fraser Valley, Howe Sound, Metro Vancouver, North Coast, North Columbia, North Vancouver Island, Sunshine Coast, West Vancouver Island, and Whistler; the heaviest rainfall of 10-15 cm (4-6 inches) is forecast over Central Coast, North Vancouver Island, and West Coast of Vancouver Island.

• Blizzard: Dempster Highway near the Richardson Mountains in Yukon Territory; strong winds and blizzard conditions with near-zero visibility are forecast through Dec. 2.

In British Columbia, authorities are maintaining a flood warning for the Sumas River and flood watches for the Coldwater, Lower Nicola, Similkameen, and Tulameen rivers, Spius Creek, Central and South Coasts, and Vancouver Island while high streamflow advisories are in effect for the Cariboo region, North Thompson region, Upper Fraser River, North Coast and southeast British Columbia. Authorities will likely issue new alerts or update existing advisories as the winter storm transits the region over the coming days.

Hazardous Conditions
Snow accumulations are likely across the affected area. Lesser accumulations are possible where sleet and freezing rain mix with the snow and the precipitation are less intense. In addition to the heavy snow, strong wind gusts will likely lead to periods of blowing and drifting snow. Blizzard conditions are possible. Sporadic power outages are possible throughout the affected area.

Transport
Multiple sections of highways 1, 5, 8, 11, and 99, as well as many other roads in British Columbia, remain closed due to heavy rain, landslides, and damage. Travel advisories are in place across portions of highways 20, 37, and 37A due to heavy snow and rain. Authorities have restricted Highway 3 between Hope and Princeton, Highway 7 from Agassiz to Hope, and Highway 99 from Lillooet River Rd to the BC Hydro Seton Lake campsite access in Lillooet to essential travel only.

The Canadian Pacific Railway has resumed operations between Kamloops, British Columbia and Vancouver Nov. 23 while the Canadian National Railway resumed services between Kamloops and Vancouver Nov. 24 after repairs were completed. The disruptions to the railways and highways have affected operations in Vancouver; the reopenings are likely to help ease the cargo backlog and supply chain disruptions across British Columbia.

Additional traffic and commercial trucking delays are possible along regional highways. Difficult and dangerous driving conditions are also likely on secondary and rural roads in the affected states as maintenance crews prioritize clearing major routes. Flight delays and cancellations are likely due to ground stops and deicing operations at regional airports.

Advice

Monitor local media for updated weather information. Verify road conditions before driving in areas where heavy snowfall is forecast. Allow extra time to reach destinations in these areas and carry an emergency kit and warm clothes if driving is necessary, especially on secondary or rural routes that could become impassable. Plan accordingly for delivery delays if routing shipments by truck through the affected area Confirm flights. Charge battery-powered devices in the case of prolonged electricity outages.

Resources

US National Weather Service
US Road Conditions
Meteorological Service of Canada
DriveBC