"Doppler is tracking a rotating severe thunderstorm just north of Bassano moving east at 25 km/hr. This dangerous storm is producing very large hail and may produce a tornado over the next 30 minutes. Communities in the path include Bassano, Rosemary and Duchess," said an Alberta Emergency Alert issued at 5:59 p.m. MT.
Environment Canada said meteorologists were also tracking a severe thunderstorm located 10 kilometres northeast of Claresholm moving southeast at 20 km/h. Golf ball sized hail has been reported with this storm in Stavely.
A tornado watch is still in effect for Okotoks, Claresholm and High River — a community recently devastated by flooding.
"Severe thunderstorms are developing in southern Alberta [and] some of these storms may have the potential to produce tornadoes," says the Environment Canada website.
"These severe thunderstorms will also have the potential to produce very large hail, flooding rain, deadly lightning and powerful winds. Use this time to secure outdoor property and to ensure family members and co-workers are prepared to take action should the severe weather approach."
If a tornado develops, Environment Canada cautions people to be prepared to take shelter immediately in a basement or reinforced structure.
"Be prepared to take shelter immediately in a basement or reinforced structure if a tornado develops," said an Alberta Emergency Alert. "Get low and put as many walls between yourself and the storm as possible. Stay away from windows, doors and outside walls. If you are on the highway and cannot avoid the tornado, seek shelter in a ditch or ravine."
Much of the rest of the southern and central part of the province, from Rocky Mountain House to Cypress Hills Provincial Park in the southeast corner of the province, has also been put on severe thunderstorm watches and warnings.
For the latest updates visit Environment Canada's website.