Severe Thunderstorm Watch in effect for:

• Sarnia – Lambton
• Watford, Pinery Park and Eastern Lambton

Conditions are favourable for the development of severe thunderstorms that may be capable of producing strong wind gusts and large hail.

Hazards: Wind gusts near 90 km/h. Hail up to ping pong ball size.

Timing: Continuing into this afternoon.

Discussion: Isolated thunderstorms over southern Ontario early this afternoon may be capable of producing nickel sized hail. A more organized area of thunderstorms over Michigan is expected to track eastward into Ontario this afternoon.

As the Great Lakes are very cold, at this time there is uncertainty as to how strong these thunderstorms will be as they cross into Ontario.

Should the cold temperatures of the lakes be overcome, a strong line of thunderstorms is expected with strong wind gusts and large hail.

Thunderstorms are expected to move east of the area late this afternoon. 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!

Emergency Management Ontario recommends that you take cover immediately if threatening weather approaches. Severe thunderstorm watches are issued when atmospheric conditions are favourable for the development of thunderstorms that could produce one or more of the following: large hail, damaging winds, torrential rainfall.