Elevated thunderstorm risk

Long Island Power crews work to restore power after heavy storms this past Sunday.

There is a decent chance of some strong thunderstorm activity today from the Ottawa Valley across eastern Ontario and southwest Quebec and into northern New York and New England. Warm and humid air is streaming north on gusty southwest winds today in advance of a potent cold front. This front has a history of severe weather since Sunday from the high plains and prairies across Northwest Ontario and the Great Lakes. Numerous reports of hail, flooding and tornadoes have occurred. We can expect the thunderstorms to flare up late this afternoon in our area. The main threat will be gusty winds and heavy rain in and around Montreal. Up to that point it will be a warm and humid day with temperatures near 30C. Thursday will be cooler and much less humid with highs reaching 25C under sunny skies.

This past Sunday a strong cold front cut into some of that tropical air on the US east coast. A line of very intense thunderstorms moved across the New York City metro area and produced an F-1 tornado with 100mph winds in the Bronx. It was the first such storm since 1974 according to one source. Numerous trees and power poles were snapped and some injuries were reported from flying glass. Power was out to thousands on Long Island.