Montreal weather turns unsettled on Tuesday as a widespread severe storm risk stretches from Halifax to Saguenay. Forecasters are watching Quebec, New Brunswick and much of the Maritimes for storms that could bring heavy rain and isolated severe weather.
The risk runs across more than 700 km and includes the possibility of up to 30 mm of rain in only a few hours. That amount could fall where storms strengthen under muggy air, even as temperatures continue moving downward after a scorching week on the East Coast.
Quebec and New Brunswick Tuesday
A low-pressure system is expected to spin up widespread storms across Quebec and New Brunswick throughout Tuesday. Forecasters also expect isolated storms to develop in parts of P.E.I. and Nova Scotia by the afternoon, keeping the storm risk spread across a broad part of Atlantic Canada.
The broadest concern is not a single storm cell but the size of the area under watch. Parts of southern Quebec and most of the Maritimes sit in the path of the same system, so showers and storms may not stay local for long before new cells form farther east.
Halifax to Saguenay
The span from Halifax to Saguenay gives the forecast its reach. People in Quebec and New Brunswick face the main storm development on Tuesday, while communities in P.E.I. and Nova Scotia may see storms later in the day if the system builds as expected.
Muggy conditions matter here because the air holds the moisture that can feed torrential rain. The forecast calls for some storms to drop up to 30 mm in a few hours, which is enough to make the heaviest cells the ones to watch most closely.
Wednesday in Newfoundland and Labrador
The system is expected to move east into Newfoundland and Labrador by Wednesday, and the forecast is looking to clear up after that. For readers in Quebec, New Brunswick and the Maritimes, Tuesday is the main window for disruptive weather, while Wednesday points to a calmer pattern farther east.
Which parts of southern Quebec face the highest impacts on Tuesday will depend on where the strongest storms build along the low-pressure system. For now, the clearest read is that the widest severe storm risk sits across Quebec and the Maritimes, with the heaviest rain threat tied to the storms that turn strongest first.
