Canada: Adverse weather forecast across parts of British Columbia and southern Northwest Territories late June 22 /update 1

Severe weather is forecast over parts of central and northeastern British Columbia and southern Northwest Territories as of late June 22. Thunderstorms and heavy rainfall are forecast across the region; strong wind gusts, lightning, hail, and possible tornadoes may accompany storms. Heavy downpours could trigger flooding in low-lying areas, and strong winds could cause property damage and power outages. Authorities have warned people in the affected area to take cover if threatening weather approaches.

Environment Canada has issued red severe thunderstorm warnings (the highest level on a three-tier scale) for the regions around Stuart - Nechako and Fort Nelson. Winds gusting up to 90 kph (56 mph), large hail, and locally heavy rainfall are possible in the affected area. Yellow thunderstorm watches (the middle level on a three-tier scale) are in effect for the rest of the affected areas, including the Lakes District, Muncho Lake Park, and Stone Mountain Park in British Columbia and the Fort Liard region, including Nahanni Butte - Sambaa K'e, in Northwest Territories. A grey special weather statement for heavy rainfall due to slow-moving thunderstorms is also in place for the Fort Nelson region, mainly around Sikanni Chief and northern Peace River, from the afternoon of June 23 through early June 25. Localized rainfall totals of 5 cm (2 inches) are possible. Officials will likely issue further weather alerts, including possible tornado warnings, in the region over the coming hours and days.

Sustained heavy rainfall could trigger flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed stormwater drainage systems. Sites downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides are possible in hilly or mountainous areas, especially where heavy rainfall has saturated the soil. Disruptions to electricity and telecommunications services are possible where significant flooding or landslides impact utility networks.

The severe weather could contribute to transport disruptions throughout the region. Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters.

Severe weather may trigger flight delays and cancellations at airports across the affected region. Flooding could block regional rail lines; freight and passenger train delays and cancellations are possible in areas with heavy rainfall and potential track inundation.

Localized business disruptions could occur in flood-hit areas; some businesses might not operate at full capacity because of damage to facilities, possible evacuations, and some employees' inability to reach work sites. Strong winds could also cause power outages.