Hail pummeled parts of Toronto Thursday as a powerful summer storm swept through the city and brought highway traffic to a standstill.

The rain began shortly after 4 p.m., falling in heavy sheets. Environment Canada issued a severe thunderstorm warning due to concerns of large hail, damaging winds, lightning strikes and “torrential” rainfall.

The strong storm is expected to strike several regions within the Greater Toronto Area and pass by mid-evening.

Videos show sheets of rain blasting roads and halting traffic along Highway 401. Other photos show an ominous wall of clouds passing over the city’s skyline and thick piles of hail on the road.