A line of severe thunderstorms is bringing damaging winds, hail and heavy rain to parts of southern Ontario on Tuesday.

Much of southern Ontario was under severe thunderstorm watches or warnings as the storms knocked out power, brought down tree limbs and flooded roads as they moved across the province.

In Orangeville, a vehicle was blown off a highway and into a ditch by strong wind gusts, said Ontario Provincial Police.

The incident was initially reported as a possible tornado, but OPP Const. Paul Nancekivell later said the vehicle went off the road due to powerful wind gusts.

There were multiple reports of downed power lines, and Hydro One was reporting electricity outages north of the GTA to Barrie and east through cottage country.

Near Alliston, several people were stranded in vehicles that were hit by falling hydro poles along County Road 10.

Because there were wires on the ground, the people remained in their vehicles until hydro crews turned off the power and said it was OK to move.

Six vehicles were struck by the poles. No injuries were reported.

Storms showed signs of rotation as they moved through the Orangeville, Whitchurch-Stouffville and Barrie areas, tweeted Patricia Martel, a hazard and risk specialist for Emergency Management Ontario.

Some CP24 viewers reported golf ball-sized hail.

In its warnings, Environment Canada said severe thunderstorms are capable of producing large hail, tornadoes or damaging winds and heavy rain.

Emergency Management Ontario urges people to take cover immediately if threatening weather approaches.

Environment Canada offers the following advice during a storm:

  • Go indoors and move away from windows and skylights
  • Avoid areas of a building that could be affected by falling debris such as tree limbs
  • Do not approach downed power lines
  • Stay on the lower floor of a home or building
  • If a storm is particularly severe, go to the basement
  • Avoid driving through water on roads because even shallow, fast-moving water can sweep a vehicle away

With files from CTV Barrie reporter Heather Wright