Much of the London area is under a severe thunderstorm watch.

Huron-Perth is under a thunderstorm warning.

A significant, widespread severe weather situation is underway across part of southern Ontario. Several clusters of strong to severe thunderstorms will continue to affect parts of the watch areas well into the evening ahead of a cold front. They will be capable of producing very strong wind gusts, large hail and heavy rain. Isolated brief tornadoes are also possible, says Environment Canada.

Very strong wind gusts can damage buildings, down trees and blow large vehicles off the road. Remember, severe thunderstorms can produce tornadoes. Be prepared for severe weather. Take cover immediately, if threatening weather approaches. Stay indoors when a thunderstorm strikes. There isn't a place outside that is safe during a thunderstorm. Stay away from all windows, skylights and doors.