[Posted Aug 26, 2024]
Get ready everyone! Another cold wave is on the horizon.
To start the explanation off, I’m going to lay out the current conditions, as always. Right now the systems that are effecting us are a high that is in Saskatchewan, a low over Hudson Bay, and finally a low pressure “complex” (as I like to call it) over the area of western NT – YK – northern BC – off the southern coast of Alaska. If you happen to know about blocking patterns, or you just watch The Weather Network a lot, you definitely now know that I’m about to write down some stuff about an omega block. If you don’t know what that is, the next paragraph should fill you in.
“Wave patterns” are patterns of the jet stream and pressure isolines that indicate specific weather conditions in areas relative to them. An “omega block” is a type of blocking pattern, which is a category of wave patterns. Blocking patterns are just wave patterns that are very organized, and don’t let any other systems through. An omega block occurs when the jet stream comes in from west, goes below a low, wraps up and around a high, before going straight back down to another low. In the area near the high, there are warm and dry conditions. In the areas near the lows, there are cool and wet conditions. Omega blocks usually take a while to break up, meaning they can bring devastating droughts a few hundred kilometres away from devastating floods. Great.
At the moment, we are right on the western edge of the high pressure area, meaning above average temperatures, but not super above average temperatures. Since the high is moving off pretty quickly to the east, tomorrow will be much more average. The interesting stuff begins tonight, when the little low over the Gulf of Alaska attempts to cross the mountains, but it just can’t do it. Therefore, it’s squeezed in by surrounding highs, before dissipating. The upper-level trough needs a new host, so it grabs on to the low up in the Northwest Territories, and “troughs” it down to northern and central Alberta, before strengthening it very fast. We could already see the troughing begin this morning!
It will really start to get going Tomorrow afternoon and evening, when the rapidly-strengthening low will stir up the atmosphere enough for some thunderstorms. Those will eventually move off, leading the way for some very heavy rain and possibly flash flooding overnight. The rain will continue until sometime on Wednesday. Wednesday will be very special for other reasons, because it is the day when the low passes right over us. This means a very cold high, and very strong winds and gusts.
Here are my predictions for the overall weather:
Tonight: Clear with a couple of clouds, and a low of 13 or 14. Gentle winds, with gusts of 40 possible.
Tomorrow: Clouds slowly shrouding more of the sky, eventually leaving us overcast. A thunderstorm or two in the mid to late afternoon with showers afterward. A cool high in the low 20s, with a gentle breeze.
Tomorrow night: Light rain in the evening, with a possible lingering thunderstorm, giving way to strong winds and gusts paired with periods of heavy rain and possible localized flash flooding overnight. Low near 10, feeling like 5.
Wednesday day: Rain tapering off with possible gale-force gusts and a high in the mid to high teens, possibly much lower though.
Wednesday night: Winds calming and clouds parting with a low near 10.
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