Environment Canada says a severe thunderstorm watch is in effect for Hamilton, Halton, and Niagara regions.

The weather agency says the storms may produce large hail, heavy downpours, and strong wind gusts of up to 100 km/h.

The severe weather is expected to hit the Golden Horseshoe late Thursday morning and afternoon.

According to an alert on Environment Canada’s website, severe thunderstorms can produce tornadoes, cause flash floods and water pooling on roads. “If you hear thunder, then lightning is close enough to be dangerous,” says the agency.

Strong wind gusts can toss loose objects, damage weak buildings, break branches off trees and overturn large vehicles. The Office of the Fire Marshal and Emergency Management recommends that you take cover immediately if threatening weather approaches.

Severe thunderstorm watches are issued when atmospheric conditions are favourable for the development of thunderstorms that could produce large hail, damaging winds, and/or torrential rainfall.