Widespread showers and thunderstorms Sunday for Montreal

Heavy rain and thunderstorms are expected on Sunday in Montreal. A heavy rainfall warning has been issued for southern Quebec and eastern Ontario for 50-75mm. This amount of rainfall is capable of flash flooding as well as ponding of water on area highways. Further south strong thunderstorms and even isolated tornadoes are possible in upstate New York and Vermont.

Heavy Rain Warning for Montreal and Ottawa.

A heavy rain warning was has been issued by Environment Canada for metro Montreal, southwestern Quebec as well as eastern Ontario. A significant severe weather outbreak is possible further south across portions of New York and New England on Sunday.

For the St. Lawrence Valley, a warm and muggy airmass remains across the region despite the passage of a cold front late Thursday. While temperatures are much cooler, atmospheric conditions remain humid and unsettled. The aforementioned front will move back north as a warm front Saturday evening, stalling along the international border and become the focus for heavy rain and thunderstorms overnight Saturday and most of the day Sunday.

At this time, 50-75mm (2-3 inches) of rainfall is possible within the most persistent shower activity. The heavy rainfall may produce local flash flooding as well as ponding of water on area roads. Temperatures will remain warm and muggy through the period, dropping to near 19C (66F) tonight and rising to 25C (77F) Sunday.

While we are not expecting severe weather in Montreal, some of the storms will have gusty winds and lightning. Outside of the storms, winds will be gusty, out of the southwest 40-60km/h.

If you have travel plans into upstate New York or Vermont on Sunday, be weather aware and keep an eye to the sky. They will be in the warm sector, with an elevated risk of afternoon thunderstorms. Some of the storms will be severe, with gusty winds, hail, heavy rain and even the possibility of tornadoes.