Another round of rain and thunderstorms for Montreal

Just about every other day this month has featured some form of rain or thunderstorms across eastern Ontario and southwestern Quebec. Some have been forecast, while others seem to pop up out of nowhere. Sadly this trend is expected to continue through  the upcoming weekend. (Valley Weather Photo)

Strong low pressure for June is forecast to deepen as it lifts northeast form the Midwestern United States down the St. Lawrence Valley towards Quebec City over the next 24-36 hours. This storm system on the weather maps is more typical of a winter storm and not one you would expect to find in June. That being said, only liquid precipitation is forecast, as it is June!

On Wednesday, clouds will begin to increase as a warm front associated with the storm moves northeast. A few showers and thunderstorms are expected ahead of the main event on Thursday. While no severe weather is anticipated Wednesday in Montreal, some heavy rain will be possible with any storms that develop.

Thursday will be a more active day, with a round of heavy rain in the morning, with as much as 30mm possible for Montreal. A few breaks in the cloud will stir up afternoon showers and thunderstorms, some with torrential rain, gusty winds and small hail. The activity should diminish by sunset. 

Rain totals over the next 4 days could easily surpass 50mm for some locations in our region. Heavy rainfall warnings are currently in effect from Sorel-Tracy towards Quebec City along the north shore of the St. Lawrence River.

Temperatures will remain in the middle 20s both Wednesday and Thursday, with overnight lows in the teens.

Gusty winds will develop with this storm system, even outside of thunderstorm activity. The winds will back from southeast to southwest on Thursday, gusting between 30-60km/h.

As the storm system moves towards the lower St. Lawrence River Valley, it will begin to slow, resulting in stubborn clouds, scattered afternoon showers and chilly temperatures for mid-June. These conditions will persist into Sunday, before yet another storm system approaches for the start of the new work week.

June has already been a wet month in Montreal, with rain falling on more than half the days already. Amounts range from 60mm (2.3 inches) to more than 100mm (4 inches) to date across the southern portions of the province. At Trudeau Airport, 61.1mm has fallen, while I have measured 73.2mm at my weather station on Ile Perrot.

Dry weather with seasonable seasonable temperatures should return for the St Jean Holiday by next Wednesday.