A tornado warning is in effect for parts of southern and eastern Ontario as a storm system tracks across the province.


Environment Canada meteorologists are tracking a dangerous thunderstorm near London, Ont., that is likely to produce a tornado.


"Doppler radar indicates strong rotation about 20 [kilometres] north of London and it is moving eastward at 60 km/h," Environment Canada said. "This is a dangerous and potentially life-threatening situation.


Tornado warnings are also posted for area between Brockville and Ottawa.


Many watches and warnings for severe thunderstorms were also posted across the same parts of the province.


People are advised take cover immediately if threatening weather approaches, Emergency Management Ontario recommends.