***As of midnight - all watches and warnings have expired.
Multiple thunderstorm cells are affecting the Montreal area at this hour. The main threat will be gusty winds and torrential rainfall. I measured close to 25mm (1 inch) of rain so far today here on Ile Perrot. The threat for an isolated tornado still exists, but it is unlikely for the Montreal region.
Earlier today, tornado warnings were issued for parts of eastern Ontario after funnel clouds were reported near Kemptville, south of Ottawa.
A severe thunderstorm watch is now in effect for southern Quebec including metro Montreal.
A tornado watch is in effect for eastern Ontario and upstate New York including Ottawa and Plattsburgh.
A watch means conditions are favorable for severe weather, a warning means severe weather is imminent. The risk for severe weather will persist through about 8pm Sunday evening in Montreal.
3:45 PM: A warm front has lifted north of Montreal early this afternoon. The air has become very moist and unstable as temperatures rise into the middle 20s. A strong cold front is moving east from Ontario. Thunderstorms are developing in advance of the front. Some of the storms have become severe, with rotation detected on doppler radar, indicating possible tornadoes.
Environment Canada has issued tornado and thunderstorm watches for the entire region. There are some warnings within the watch area across eastern Ontario. The main threat with the storms this afternoon will be strong winds up to 100km/h, torrential rain and some isolated tornadoes. Keep an eye to the sky if you are outdoors.
In the event of a tornado, or if a tornado warning is issued for your area, it is recommended you take the following actions: Go indoors to a room on the lowest floor, away from outside walls and windows, such as a basement, bathroom, stairwell or interior closet. Leave mobile homes, vehicles, tents, trailers and other temporary or free-standing shelter, and move to a strong building if you can. As a last resort, lie in a low spot and protect your head from flying debris. Lightning kills and injures Canadians every year. Remember, when thunder roars, go indoors!