A severe thunderstorm watch was upgraded to a warning by Environment Canada for Sarnia-Lambton.
The weather agency says these thunderstorms may be capable of producing very strong wind gusts, large hail and heavy rain.
The warning was ended around 3:06 p.m. Saturday and a watch remained. A watch also remains in effect for Strathroy-Komoka and Western Middlesex County.
Around 8:40 p.m. Environment Canada issued another severe thunderstorm warning for Watford - Pinery Park - Eastern Lambton County, Sarnia - Petrolia - Western Lambton County.
Around 10:28 the severe thunderstorm warning was ended for Sarnia and Western Lambton County.
Very strong wind gusts can damage buildings, down trees and blow large vehicles off the road.
Remember, severe thunderstorms can produce tornadoes.
Heavy downpours can cause flash floods and water pooling on roads.
Lightning kills and injures Canadians every year. Remember, when thunder roars, go indoors!
The Office of the Fire Marshal and Emergency Management recommends that you take cover immediately if threatening weather approaches.
