Storm Season

There’s always a bit of nervous excitement surrounding storm season for Southern Ontario.  While we want to see some picturesque storms, we also hope that they don’t do much damage. It’s a bit of wishful thinking because severe storms are often accompanied by strong wind, heavy rain, and hail; the very things that give them the ‘severe’ designation.  

The Great Lakes that surround Southern Ontario can have a serious affect on local weather.  Those large bodies of water greatly influence air temperatures and moisture, and they often provide fuel for things come storm season.  On really hot days in the summer, the wind can draw cooler air from the lakes and create isolated thunderstorms along what are called lake breeze boundaries – over land close to them. The lakes can also be barriers to propagation of storms at times as well; the colder air over the lakes can be storm ‘killers’ at times by denying the fuel severe storms need. 

This year has some special scenarios giving rise to the nervousness, for me.  The past winter was very mild.  In a typical winter, the Great Lakes will form a lot of ice.  Some lakes will see incredible amounts of ice with the whole Great Lakes basin seeing close to 50% of the water surface frozen.  This year we had historic lows for coverage and by mid February coverage was at around 3%. Ice coverage keeps Lake water cold, and the time it takes for the water to warm up to the point where it adds fuel to storms often means we don’t see our ‘storm season’ getting fired up properly until early July.  The nervousness comes because of the lack of ice and what warmer waters may mean for storms this summer. 

In 2023, by mid June, Southern Ontario had two tornadoes and 3 ‘wind events’ in total.  In 2022, by the same date, we had one tornado and seven wind events (six of which were tied to the derecho on May 21st).  The 2021 year saw similar numbers (one tornado, and two wind based events in total). To this point in 2024, we have had one tornado but eight wind events in total. Excluding the derecho event (it was a unique day), this year is looking busy. Given the current heat event, and the warmer Great Lakes due to a lack of winter ice, this year is shaping up to be stormier than normal.  Not exactly scientific conclusions but more gut instinct. I’m no meteorologist but I forecast (see what I did there) this year will continue the trend of having more than average numbers of wind events and tornadoes.

Be weather aware 😉