Scattered showers and thunderstorms, capable of producing strong wind gusts and heavy rain, developed Monday.
Local rainfall amounts of 20 mm to 30 mm (an inch or more) are possible Monday afternoon and evening in slow-moving storms.
Weather radar was showing clusters of thunderstorms forming east of Sarnia and throughout Lambton County.
Environment Canada issued a severe thunderstorm watch for Sarnia-Lambton at mid-afternoon, but it was ended just after 6pm.