Instability in the air: Weyburn's stormy outlook

So far, the month of July has been one of the driest on record. Before this morning, Weyburn had seen just 7.2 millimetres of rain. Now, 12.8 millimetres have fallen on the Opportunity City, making this month the 4th driest July on record. However, if the outlook from Environment and Climate Change Canada holds true, we could see a lot more precipitation before the month is officially over.  

“It shows a risk of thunderstorms, which might bring some pretty strong wind gusts, large hail and some heavy rain in the local areas,” meteorologist Stephen Berg said of the outlook issued this morning. It shows Weyburn, along with the southeast corner of the province south of the Trans-Canada and east of Highway 6, as being at a high risk of severe thunderstorms. 

The outlook is calling for, if the storms develop, wind speeds of up to 110 km/h, hail that is 4-6 centimetres in diameter, and up to 50 millimetres of rain.

“Currently the heat and humidity are bringing very strong instability in the area that would help with the severe storm production if one were to develop today,” Berg added. 

The MLCAPE, or mixed layer convective available potential energy, of the system moving through southeast Saskatchewan ranges between 2000 and 3000 J/kg. It is the measure of the instability in the troposphere, a layer of the overall atmosphere. The higher the number, the more potential energy in the air that can feed the storm.  

“Those levels of instability can result in quite large hail and strong wind gusts as well from the thunderstorm,” Berg added.  

The system is expected to move into the area in the late afternoon, with Berg not expecting thunderstorms to start to develop until around 4 or 5:00 p.m. and then the system should move off towards Manitoba by around 10:00 p.m. 

With the potential for storms existing, Environment and Climate Change Canada issued a severe thunderstorm watch for Weyburn, along with much of southeastern Saskatchewan. A watch is issued when the conditions are favourable for severe thunderstorms that may be capable of producing strong winds, large hail and heavy rain. Environment Canada has also stated there is a non-zero risk of a tornado developing with the system.  

Stay up to date with the latest by checking the Discover Weyburn Weather page.