Wind gusts, heavy rain and even hail are possible, Environment Canada says
A storm "capable of producing damaging wind gusts, large hail and torrential rain," is possible, the release said. "Isolated tornadoes are also a risk. Be prepared for severe weather.
Residents are advised to take cover immediately if threatening weather approaches.
"Remember, when thunder roars, go indoors. Emergency Management Ontario recommends that you take cover immediately, if threatening weather approaches."
For more information, got to www.emergencymanagementontario.ca/english/beprepared/beprepared.html.