Western drought holding pattern will need something significant to break it


With the start of summer, and hot-hot-hot temperatures across the Prairies, it’s got many asking: will we see any rain?

To help us address that question is Drew Lerner of World Weather Inc.

Lerner says the last time we saw this dry weather bias pattern — pretty similar to the one we are seeing right now — was back in 2003. The difference between 2003 and this year however, is that we have an extra year of dryness behind us that we are dealing with.

“We’re in our fourth year of droughty weather in some parts of the Prairies. That makes a big difference. In 2003 we had a 2001/2002 event that preceded it, but it didn’t seem to be quite as extreme as we are right now,” says Lerner. “There are a lot of similarities between the two years, and with a pattern that we are seeing prevailing in the atmosphere, I think we can look at 2003, and come to some conclusion about where we are going down the road.”

The other years we can take a look at closely and see a lot of similarities to is 1967, and 1985. Understanding the history and the patterns is of course important, but it’s got many wondering, “OK, but how do we break this pattern? What needs to happen?”

“The unfortunate part of this is that there’s not a lot of good reason for the pattern to break. We’ve got basically a ridge of high pressure that continues to build stronger periodically over western North America in response to the drought itself,” Lerner notes. “Just merely the fact that we have so much dry real estate from Canada to Mexico has created what we call a thermal low — and what that means is we’ve heated up the air and the ground very quickly in these areas, so that a broad base of area of basically low pressure has evolved, where the air is rising dramatically over all that area. And with all of that rising air, you’re getting the air to also heat up and dry down at the same time, so the end result is that you’re building a high pressure system a lot in this environment. Until we can do something to bring large amounts of moisture into this environment, the whole mechanics supporting the high ridge of high pressure are going to remain.”

Long story short — we need a large storm system to come in, something that will “break” the ridge and the pattern we’ve got going on. The other option — albeit a less likely option, but still there — is bringing monsoon moisture up through Mexico into the U.S. Rocky Mountains, and into the Prairies.

Unfortunately, for any of this to happen, we’ll likely have to wait for some seasonal changes to take place, says Lerner.

“As we forward into June, July, and August, the thing that happens is the jet stream goes further into the north, it gets weaker, and the weaker it gets, the more difficult it is to get a storm system of size to come in and slam against that ridge and break it down. The unfortunate part is, we may have to wait awhile for any serious breakdown to take place,” Learner explains.

One of the ways we can mange through this waiting period is lower temperatures. As we know well, the moisture disappears at a rapid rate when we get above that 35 degrees celsius. As far as what the group at World Weather Inc is anticipating this year, the ridge is going to be more robust — larger in size, greater amplitudes, greater breadths to it — it’s going to be much harder to get it to break down.

“If you’ve noticed, we keep bouncing back and forth. We go real cool, and then we go back to hot again. That is indicative of this drought. The low humidity in the air by allowing the temperatures to drop and rise very quickly, because there is no moisture there to act as a buffer. There is still potential that we could cool down, but my concern as we go deeper into the summer and all that heat rises up off the Rocky Mountains and the Great Basin of the U.S., and the ridge just ends up being stubborn or persistent, it’s going to be really hard to get more of that cool air to come in as often as we’ve been seeing it,” Lerner says.

The little bit of good news amongst all of this: if you are in eastern Saskatchewan or Manitoba — further away from the Rocky Mountains — you are likely to see some of these cooler temperatures.

Check out the full conversation between RealAg Radio host Shaun Haney and Drew Lerner, below:

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