Environment Canada issued severe thunderstorm warnings twice for Sarnia-Lambton Wednesday afternoon.

A severe thunderstorm watch was elevated to a warning as meteorologists tracked an intense storm cell that formed suddenly at mid afternoon.

It moved just south of Sarnia and then southeasterly across Lambton County through the Petrolia and Alvinston areas.

The storm had the potential to produce very strong wind gusts and dime to nickel size hail.

The warning ended just after 5pm but a second warning was issued just before 6pm for eastern Lambton County for a second thunderstorm that was capable of producing very strong wind gusts, dime to nickel size hail and heavy rain.

The thunderstorm northwest of Alvinston was tracking southeast at 30 km/h.

The second warning ended at 6:30pm.

An approaching cold front triggered the storms.