Tornado warnings have been issued in many areas in Wheatland County east of Calgary, including Strathmore, Gleichen, Hussar, Rockyford and Rosebud.
Calgarians cleaning up debris from yesterday's storm are being advised to take cover.
"More thunderstorms have developed to the west of Calgary near Priddis and are moving east at 10-15 km/h towards the south and central parts of the city," said Environment Canada on its website.
The storms are capable of producing strong wind gusts, hail the size of loonies and heavy rain.
Severe thunderstorm warnings have been issued in several areas, including Calgary.
Emergency plan activated
Calgary's municipal emergency plan was activated Wednesday afternoon. The city is reminding citizens to take precautions for the extreme weather:- Stay indoors.
- Stay away from manhole covers, drains and flooded areas.
- Do not drive through flooded areas, such as underpasses.
- Avoid storm water ponds and storm drains, and do not let children play near them.
- If you experience basement seepage or overland flooding, call 311 to report.
- If you or someone else is in imminent danger, call 911.
"One of the beauties of living near the mountains is that we can expect this weather to constantly change," said Calgary Emergency Management Agency deputy chief Sue Henry.
"So this will be a dynamic situation throughout the afternoon, and we'll continue to monitor and update as necessary."