A trough extending out from a low-pressure system in Alberta could bring some substantial rains to southeast Saskatchewan today.  

“There will be synoptic rain, so that’s rain associated to the low-pressure system itself, and with that embedded thunderstorms as well,” explained Natalie Hasell, a meteorologist with Environment and Climate Change Canada. The Weyburn and Estevan area could see upwards of 25 millimetres of rain, but that could go up if a thunderstorm passes over.  

“Some forecasts are calling up to 40 or 40 millimetres,” Hasell continued. “We could see some hail, we could see some strongish winds, although we’re not really expecting warning criteria with this system. But, considering how much rain some areas in the southern prairies have seen recently, maybe we don’t need warning criteria for this to be a problem, so pay attention to what’s going on around you and be flexible in your plans.” 

After the rains pass over, the forecast is calling for sunshine and seasonal temperatures for the southeast, although the chance of more rain as the week goes on isn’t outside the realm of possibility. Hasell said some of the models show another system could make its way through the central prairies later this week, and that could possibly impact this corner of the province.  

There is also the possibility of daytime heating helping to contribute to thunderstorms. Hasell noted daytime heating can destabilize the atmosphere, providing one of the ingredients needed for a thunderstorm to develop.  

“You need low-level moisture, you need an unstable atmosphere, and then you need something to start the vertical motion for thunderstorms to form,” the meteorologist elaborated, adding the low-level moisture will come thanks to the rains today. 

“It’ll be the question of the instability, and then whether we have anything that can start the vertical motion.”