Edmonton and surrounding areas are under a severe weather 'orange' alert as Environment Canada forecasts another wave of heavy rain, with 40 to 70 millimetres expected over the weekend. The orange alert indicates conditions likely to cause significant damage, disruption, or health impacts, a step above the yellow warning.
Record Rainfall Within Reach
With 203 mm of rain already recorded this month, Edmonton is poised to break the 112-year June rainfall record of 216.5 mm set in 1914. The city's all-time monthly rainfall record is 282 mm, set in July 1901. Matt Loney, a meteorologist with Environment Canada, said, 'I would say reaching the second most rain ever in a month is a strong bet, and I think with the amount of rain we could get this weekend, we will get into striking distance of the July 1901 record.' He added that embedded thunderstorms could increase the chance of breaking the all-time record.
Flooding and Infrastructure Concerns
The ground in the Edmonton region is already saturated from near-record June rainfall. The new rainfall could cause overland flooding, washouts, and impacts to infrastructure and property. Loney noted that some areas haven't had enough time to drain, and the incoming low-pressure system could exacerbate the situation.
Widespread Impacts
Heavy rain last weekend forced some golf courses to temporarily close and led to the postponement or cancellation of hundreds of minor sports league games. On Thursday, the City of Edmonton closed the east sidewalk on the High Level Bridge due to slope instability from the previous rains causing areas of erosion near the southeast side.
Broader Weather Pattern
Loney explained that the persistent wet pattern is due to upper low-pressure troughs dropping in from the Pacific Northwest, which are conducive to developing low-pressure centres that draw in moisture. 'So far this spring, early summer, we’ve seen that this kind of atmosphere has established itself,' he said. Areas west of Edmonton, around Edson and into the Foothills near Calgary, could see up to 100 mm of rain this weekend.
Looking Ahead
July does not appear drier. Loney warned that after the storm leaves Sunday, Monday may bring a brief reprieve, but another upper trough is expected to descend, likely generating more thunderstorms and showers. 'The early portion of this summer, these upper troughs have played a major role in the weather picture,' he said.
