Special Weather Statement for Montreal
UPDATE, June 27, 8AM: Partial sunshine will give way to clouds and heavy rain across southern Quebec from late Friday evening through Saturday. Between 25 and 50mm (1-2 inches) of rain is possible, with isolated heavy thunderstorms along a warm front Friday night and early Saturday morning. Expect ponding of water on highways, along with some localized flash flooding. No major river flooding is anticipated at this time, with very dry conditions so far in June. Only 25.2mm of rain has fallen at Trudeau Airpot since June 1st.
Previous Post: After the searing heat and humidity of this past week, conditions have turned much cooler on this Thursday in Montreal. On Tuesday, Montreal recorded its warmest June day since weather records began at Trudeau Airport, reaching 35.2C (95.4F). This surpassed the previous monthly high of 35.0C (95F) set back on June 9, 1980.
A series of weak disturbances have introduced cloud cover and a few showers Thursday, keeping temperatures much cooler. The forecast high for Montreal is 23C (73F).
Our attention will turn to a significant surge of moisture arriving ahead of the same warm and humid air mass that was present earlier this week. The heat dome will push a warm front north, approaching southern Quebec late in the day Friday.
Currently, forecasters expect a swath of very heavy rain and thunderstorms to set up just north of that front. Copious amounts of rain are forecast, with 25mm to as much as 75mm聽(1 to 3 inches) possible for some locations. Heavy rain and/or flood watches and warnings may be needed fro some regions as the event draws closer. Stay tuned if you have any weekend outdoor plans.
The heaviest rain would fall from late Friday into Saturday for southern Quebec.
What is not clear at the moment is where that swath of rain will be. Models have it anywhere from central New York to right over the Montreal region. Where the most persistent heavy rain does occur, flooding will be a real possibility.
The clouds and rain will keep temperatures around the 20C (68F) mark Saturday. Skies clear Sunday, along with a warm high of 26C (79F). Once the rain ends, a warm and humid air mass will remain through Canada Day, with highs approaching 30C (86F) once again. More unsettled weather in the form of showers and thunderstorms is possible next week.