A large high-pressure system that has stalled over the Prairies is largely to blame for warm, dry conditions that have persisted across much of the West this year.
Trevor Hadwen, agroclimate specialist with Agriculture Canada, said the system is splitting the jet stream, forcing currents north into the parklands or south into the United States.
Aside from some isolated thunderstorm activity, the Canadian Prairies are warm and dry, and there’s no way to tell when the stalled system will move on.
“In the last (little while) we’ve been seeing a lot of moisture and a lot of rain moving through the very southeast portion of Saskatchewan and down into the United States,” said Hadwen.
“Southern Manitoba is getting a little bit of rain and southeastern Saskatchewan is getting a little, but most of the rainfall this year is happening just to the south of us.”
He said it’s not unusual to see a large weather system lose momentum.
A system that stalled over Eastern Canada last winter delivered record snowfall to some parts of the country.
Unfortunately, there is no way to predict how long it will take to dissipate.
“It’s not abnormal to have a stalled system but it’s a little bit abnormal to have a system stall for so long in one place, like this one has,” Hadwen said.
“It’s been in place now for a very, very long time, pushing the moisture north and south of (us).”
A late-developing El Nino has compounded the problem and appears to be gaining momentum as the summer approaches.
Normally, El Nino systems that affect Canadian weather have a greater impact on winter temperatures.
The El Nino of 2015 was late to arrive and late to develop. Now that it’s here, it is beginning to influence the weather in a typical fashion, delivering warm, dry air to the Prairies.
“From a prairie perspective, El Nino is typically something that we (consider to be) a winter phenomenon,” said Hadwen. “We tend to get warmer, drier winters and it’s generally viewed as a good thing.
“This El Nino started up last year and it was very, very weak going into the winter but now it has started to really gain some strength.
“Typically, we don’t talk about an El Nino summer so this one’s a little bit different in that respect.”