weather

We saw a strong ridge of high pressure build in last week, which brought daytime highs into the low thirties across parts of the eastern Prairies. Once the ridge collapsed, cooler air moved back in. Well, it looks like we can expect another cycle of building and collapsing ridges. Then, starting on the weekend, the weather pattern should become more energetic thanks to a strong trough of low pressure forecasted to develop off the West Coast.

Well, one week is up and as I pointed out in last week's forecast, the weather pattern still looks like it is going to flip from a cool-ish spring regime right into a summer-like pattern. This flip should happen over the next few days.

We start this forecast period with an area of low pressure exiting the eastern Prairie and taking the rain and wet snow with it. To the west, a weak frontal system looks ready to drop into northern Alberta where it should bring scattered showers.

Spring is the toughest time to forecast, but this spring is being particularly tough. The atmosphere is in a very meridional flow right now. That means there are lots of troughs and ridges. So, instead of a persistent westerly flow across our region we are seeing warm southerly flows as ridges build, followed by cool northerly flows as the ridges collapse and are replaced by troughs of low pressure.

When we have these battles between warm and cold air, there's always a good chance for a storm system or area of low pressure to develop. We've seen this happen a few times this spring and looking at the latest medium range weather models, the Prairies are likely in for a few more storms as the battle continues.

This forecast period looks to be be defined by two areas of low pressure, one spinning off the west coast and the other spinning over eastern Canada. Exactly how these two lows behave a move will have a big impact on temperatures across the central and eastern Prairies.

We start this forecast period with a strong area of low pressure pushing in off the southern coast of B.C. This low will bring very mild temperatures to southern Alberta on Wednesday and into Thursday. It will then help to develop an area of low pressure over south-central regions early Thursday morning.