It was a decent spring for precipitation in Jasper National Park, but predicting how much rain – or snow – the destination will get this summer is a taller order than even the experts can affirm.
“While there is a subtle signal of below normal precipitation totals across central Canada, it is pretty spotty looking,” said Jennifer Smith, national warning preparedness meteorologist with Environment and Climate Change Canada (ECCC) during the national weather agency’s summer seasonal outlook presented on Tuesday.
Between March 21 and June 10, there were 50.8 mm of total precipitation measured at the Jasper Warden Station where Environment and Climate Change Canada (ECCC) tracks weather systems. Data wasn’t available regarding Tuesday’s rainfall before press time.
“Typically, if we see a little bit over one or 2 mm, you can think of that day as a rainy day,” said ECCC meteorologist Alysa Pederson.
Tuesday’s rain event was part of a storm system that developed and moved across the Rockies with a jet stream that contributed to thunderstorms developing near Edson.
“We were under a bit of an upper ridge,” Pederson said.
“It was a little bit warmer yesterday, but today it transitioned to a system moving through in Alberta, bringing the unsettled weather. And then, of course, with the Rocky Mountains, it could trigger all sorts of thunderstorms this time of year.”
Spring brought early drought conditions and wildfires to both British Columbia and Alberta. Recent rains have helped greatly to bring most of those problem areas under control. The northeastern corner of B.C., however, is still dealing with several out-of-control wildfires, which includes one wildfire of note near Patry Creek.
The springtime moisture has helped to keep the grass and trees green, but it’s still nowhere near being the wettest events on record. In 2004, for instance, there were four early June days that combined saw more than all that with 57.2 mm of rain.
The ECCC predicts below-normal precipitation across most of Canada will continue into the summer months.
“Precipitation, especially in the summer months, is a really hard thing to really capture when you're looking at seasonal outlooks like that,” Pederson said.
The reason for this is that seasonal forecasts use climate models to predict what temperature and precipitation might look like in the coming seasons, Smith explained.
“Like a three-month snapshot into the future, these forecasts are a little bit different from a weather forecast because they account for the larger global climate system, such as ocean and atmospheric circulations,” she said.
Even the ECCC’s weather page of current conditions and seven-day outlook for Jasper shows a weekend of showers. Often, these precipitation events come with the risk of thunderstorms, Pederson said, which bring their own hazards. The suspected cause of the Patry Creek wildfire was lightning.
“A lot of our precipitation in June (more so in July and August) comes from thunderstorm activity,” Pederson said.
“As you can imagine, especially in the summer for thunderstorm activity but especially in the mountains, where there's a lot of terrain, even our day one models have a harder time in the mountains when it comes to thunderstorm activity.”
As for daytime temperatures, that is easier to predict for the summer than rainfall.
“While there's not really a clear signal for the summer season in terms of precipitation, Canadians need to be ready for a warmer summer that could be met with drier conditions across the country,” Smith said.
