Heavy rain and snowmelt spark flood warnings across Alberta

Southern and central Alberta are bracing for significant flooding this weekend as unseasonably warm temperatures give way to heavy rain and rapid mountain snowpack melt.

Environment Canada is forecasting up to 100 millimetres of rain beginning Saturday night and continuing into early next week, with Calgary expecting between 50 and 90 millimetres. The forecast high in Calgary on Friday is 27 C — about 10 degrees above normal — before dropping to around 10 C by Sunday.

Rising water levels have already prompted flood watches for the Pipestone River and the Bow River near Lake Louise. Emergency officials in Banff have deployed temporary flood barriers in vulnerable spots. Parks Canada warns that unseasonably warm temperatures combined with heavy rain also increases avalanche danger, advising backcountry users to avoid avalanche-prone areas.

Calgary emergency officials are monitoring the Bow and Elbow Rivers closely. While the city says no widespread flooding is expected at this time, residents are being asked to exercise caution around rivers and low-lying areas. Homeowners should ensure eavestroughs and extensions are directed away from homes and garages, keep community storm drains clear of debris, and report any pooling water to 311.

The city of Lethbridge is warning residents to prepare for a "significant downfall" and advising against driving through large puddles or venturing into the coulees, where trails can be slippery and dangerous. Rain is expected to ease off Tuesday night into Wednesday.