Strong thunderstorms are possible on the Niagara Peninsula and east of the GTA to Montreal today, with a variety of convective threats.
The triple point of the surface low associated with the storms will move from Ottawa to Montreal this evening, and a squall line will be contained within the narrow warm sector. Although the potential for severe weather encompasses most of eastern Ontario, the highest likelihood of severe thunderstorms with damaging winds (which should penetrate a slight temperature inversion), frequent lightning, and heavy rain (over 75 mm possible locally) will exist near the St. Lawrence Seaway from Kingston to Montreal. A storm may also produce large hail in the Seaway early in the evening.
Important notice for S QC readers: The ground remains very wet in and around Montreal as flooding continues in the Mauricie region. Not only will river flooding increase in intensity today, many streets and basements will likely flood due to the heavy rainfall rates that are expected this evening! Take caution!