Environment Canada has placed a rainfall warning over Cochrane and the surrounding area.
"Thunderstorms currently developing on the foothills near Calgary will push northeast this evening, and merge into a large area of heavy rain tonight."
"Total rainfall amounts of 40 to 60 mm are likely to fall in a 12-18 hour period. This rain event will come to an end by late Sunday morning."
The heavy rain could cause flash floods and water pooling on roads. There is also a chance of localized flooding in low laying areas.