Originally published on July 10, 2024, on AGCanada
By Daniel Bezte
The expected shift in the weather pattern materialized as forecasted, as a building upper ridge brought sunshine and heat to the Prairies. The surprise was just how warm that upper ridge was. Temperatures are pushing well into the thirties over a large portion of Alberta and Saskatchewan.
For this forecast period, it looks like the upper ridge will slowly flatten and drop southwards as a series of weak lows track across the northern Prairies. This will result in a reduction in the extreme temperatures. Daytime highs and overnight lows should fall back to more seasonable values.
While it doesn’t look like any strong storm systems will hit the Prairies, several weaker disturbances bring the chance of scattered thundershowers or the occasional thunderstorm every couple of days.
The weather models are hinting that the upper ridge may start to rebuild late in the forecast period. Should this materialize, expect a return to hot, humid conditions starting in Alberta and then spreading eastwards late next week.
Alberta
Alberta should see a couple more days of heat before the upper ridge begins to break down. When it does, it will allow cooler, more seasonable temperatures to move in. Expect plenty of sunshine on Wednesday and Thursday. With the heat, humidity, and a weak low riding the top of the ridge there will be the chance of a few afternoon thunderstorms.
Surface high pressure will build in on Friday and Saturday bringing sunny skies and daytime highs in the mid to upper twenties. Late on Saturday and into Sunday, a weak disturbance is forecasted to move into south-central regions which will bring the chance of some showers and thundershowers.
Early next week, the weather models are showing a fairly strong surface high building across the eastern Prairies. This high will help build an upper ridge to the west. This means a return to hotter temperatures. Forecasted highs on Tuesday and Wednesday are expected to be back into the low thirties.
The southeasterly flow around the eastern surface high will help to trigger afternoon thunderstorms over western regions on Tuesday and Wednesday afternoon.
Saskatchewan and Manitoba
The center of the upper ridge is forecasted to move through Saskatchewan on Thursday and through Manitoba on Friday. As the ridge drifts eastwards, it will weaken and collapse to the south. This means that the likelihood of temperatures in the mid-thirties will be low. With that said, daytime highs will be in the low thirties in most regions. Combined with fairly high humidity and overnight lows in the upper teens, conditions will be uncomfortable.
As the ridge collapses to the south on Friday, an area of low pressure will slide through the northern Prairies. This will drag a weak cold front through Saskatchewan on Friday and through Manitoba early on Saturday. Expect a mix a of sun and clouds and the chance of thundershowers or a heavier thunderstorm as the front moves through. At this point a severe weather event doesn’t appear likely.
Behind the front, temperatures will cool with highs forecasted to be in the mid twenties.
On Sunday, a weak low is forecasted to track across the southern halves of Saskatchewan and Manitoba. This will bring a mix of sun and clouds and some showers, with the possibility of a few thundershowers. This system should move fairly quickly and should be out of Saskatchewan by mid-day Sunday and out of Manitoba by that evening.
Behind this low, the weather models show a strong surface high building in from the north. This high will bring plenty of sunshine, starting Tuesday, along with a couple of days of cooler weather. Should this high materialize, expect daytime highs in the low twenties with overnight lows dropping down to around 10 C.
Looking further ahead, there are indications of another short heat wave building in for the second half of next week.