Canada: Severe weather forecast across parts of central and southern Quebec through Sept. 8 /update 1

Severe weather is forecast across parts of central and southern Quebec through at least Sept. 8. Heavy rainfall is expected over the region, with rainfall totals of around 3-7.5 cm (1.2-3 inches). The heavy downpours may cause flash flooding, flooding in low-lying areas, and ponding on road surfaces. Environment Canada has issued a red rainfall warning (the highest level on a three-tier scale) across the affected area. Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming hours.

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 rain has saturated the soil. Disruptions to electricity and telecommunications services are possible where significant flooding, landslides, or strong winds impact utility networks.

Floodwaters and debris flows will likely render some bridges, rail networks, or roadways impassable, impacting overland travel around affected areas. Ponding on road surfaces will cause hazardous driving conditions on regional highways. Authorities will probably temporarily close some low-lying routes that become inundated by floodwaters.

Severe weather will likely trigger intermittent flight delays and cancellations at regional airports, though these are unlikely to be severe or prolonged. Flooding will probably block regional rail lines; freight and passenger train delays and cancellations are likely in areas with heavy rainfall and potential track inundation. Localized business disruptions are probable in low-lying areas.