A Severe thunderstorm warning is now in effect for North Bay, Mattawa, French River, Powassan and West Nipissing.

At 5:34 p.m. EDT, Environment Canada meteorologists are tracking a severe thunderstorm capable of producing very strong wind gusts, up to nickel size hail and heavy rain.

A very strong storm 20 km north of Markstay is moving east at 50 km/h. This storm may have the potential to produce a tornado.

Heavy downpours can cause flash floods and water pooling on roads. Large hail can damage property and cause injury. Strong wind gusts can toss loose objects, damage weak buildings, break branches off trees and overturn large vehicles. Remember, severe thunderstorms can produce tornadoes. Lightning kills and injures Canadians every year. Remember, when thunder roars, go indoors!

Severe thunderstorm warnings are issued when imminent or occurring thunderstorms are likely to produce or are producing one or more of the following: large hail, damaging winds, torrential rainfall.

The Office of the Fire Marshal and Emergency Management recommends that you take cover immediately if threatening weather approaches.

Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to ONstorm@canada.ca or tweet reports using #ONStorm.

Filed under: Environment Canada, thunderstorm warning