It has become a theme for the first half of June. Temperatures are in the high 20s and low 30s, with the humidity making it feel even hotter. Then, the watches and warnings start to get issued for the possibility of severe thunderstorms.
Stephen Berg is a developmental meteorologist with Environment and Climate Change Canada. He explained that the components are there for a storm to develop.
“Certainly quite a bit of moisture still in the area, and some wind shear aloft,” Berg said. “And yeah, quite a bit of instability that would produce potentially severe thunderstorms, if they occur.”
The thunderstorm outlook for the prairies, issued Thursday morning by ECCC, indicated there is a moderate risk of a severe thunderstorm developing for a stretch of the province that covers the Weyburn area and much of the southeast. If the storms develop, wind gusts up to 90 kilometres an hour can be expected, along with hail and up to 75 millimetres of rain.
The conditions described in the outlook are also ripe for the development of storms, with MLCAPE values of 2500 joules per kilogram. Standing for Mixed Layer Convective Available Potential Energy, the higher the number, the more energy in the air. The more energy in the air, the higher the potential for a thunderstorm to develop. With this being factored in, the outlook says there will likely be severe multicell thunderstorms. Where those develop, and the direction they will be moving in, is still a bit undecided.
“It looks like the overall mid-level, low-level circulation is from the north, potentially, so there might be some storms that travel from the north, but also, there is a decent flow from the southwest, so depending on where the storm originates it might get into some more southwesterly flow,” Berg pointed out.
The cycle seen in the southeast over the past week has also played a factor in the development of the storms, as it creates almost a self-feeding system.
“The pretty robust surface moisture and evapotranspiration from plants, those are certainly part of it,” Berg said of the cycle. There is also quite a bit of moisture moving up into the region from the United States, which is another one of the key ingredients for the development of repeated thunderstorms.
The next few days, though, could see things stabilize with a lower potential for storms. However, the situation will continue to be monitored by Environment Canada.