This week will be quite nice, as a fairly consistent summer-like pattern takes hold.
24°C / 12°C
Today will be coolest day of the week, but that isn’t actually a bad thing in this case. We should see temperatures climb into the low to mid twenties with light northerly wind. Some smoke from forest fires in northern Canada may trickle into southern Manitoba, but otherwise skies should be mainly clear.
26°C / 14°C
Tuesday look very similar to Monday, except it’ll be slightly warmer. Temperatures in the mid twenties are expected once again, with a light northerly wind. Again, there may be a bit of smoke around, but otherwise it’ll be another great day.
28°C / 16°C
Mainly Sunny. Slight chance of a shower or thunderstorm.
Wednesday should see pleasant continue continue. Temperatures will likely reach the upper twenties in most areas, once again under a light northerly flow. Wednesday’s airmass looks to be a bit more humid than what we saw earlier in the week, so a few pop-up showers and/or thunderstorms are possible in the afternoon and evening. However, these will be very hit and miss, so most people will not be affected.
The long range forecast is looking good. Models depict a large upper ridge building over the Prairies this week. That should mean generally hot and dry weather for us. Long range models suggest this ridge may stick around for most of the next 10 days.
An unusually strong upper level low for this time of the year nosed into the southern Prairies and was the focus for severe storms last Thursday. All the ingredients were present for severe storms that day, as Brad alluded to in his discussion of the event posted on the day of. Keeping in mind that this might be one of the last chases this season, due to the jet stream slacking up, a few of us made our way into Saskatchewan to chase the storms.
The day was off to somewhat of a surprising start as we woke up early to find a large squall line was sweeping across southeast Saskatchewan, southwest Manitoba and North Dakota. Thankfully, as the squall line moved away from the main instability axis in the morning it started weakening and its leftover cloud wouldn’t hamper our chances in Saskatchewan for the surface based storm development in the afternoon. After determining that skies would clear in the south-central part of Saskatchewan by late morning, the chase was on. From Winnipeg we drove straight to Brandon, grabbed a quick bite to eat and from there made our way to Weyburn, SK. After arriving in the mid-afternoon, we took a quick look at the satellite only to see some bubbling cumulus and even towering cumulus well to our southwest. By then it was obvious that nothing would fire in the Weyburn area with a stout cap present and no trigger around.
We then had to make a decision to either call it a day or head to south-central SK – where there was plenty of upper forcing and a cold front in the region (further west than what the models were showing). Since we were already that far into SK, we went all in and drove a good 100km west to the Assiniboia region. By the time we got there a couple supercells had already fired; we picked the one that looked best (just south of Assiniboia) and stuck to it.
Following it for over two hours, we were able to spot two funnel clouds. One may have touched the ground, but we were too far away to tell (hence lack of pictures) while the other a brief funnel that spun up later in the evening on the leading edge of a bow echo. We followed the storm which evolved into a line with multiple bow echos embedded along it. Later in the evening the line became elevated, eliminating the wind threat but still able to produce a lot of cloud to ground lightning. The complex eventually died off in southwest Manitoba and left a large area of stratiform rain in the area.
Overall it turned out to be a fun chase day, with a storm that teased us with a few funnel clouds, combined with good structure and a nice light show. What we didn’t see from that day were the large hailstones that were later reported as well as strong wind gusts of 119km/h reported in Assiniboia.
Unsettled weather will mark the start of the last weekend of July, but conditions will improve for a rather pleasant end and persist into a fairly dry and seasonal start to next week.
Friday: Thunderstorms Possible
25°C / 15°C
Chance of showers or thunderstorms
Today is off to a cloudy start with a few showers likely through the Red River Valley as the remnants of the overnight activity push off to our east. Skies will remain mostly cloudy until the cold front that brought copious amounts of severe weather to Saskatchewan yesterday pushes through the Red River Valley early this afternoon.
As that cold front moves eastwards, it’s likely that more thunderstorms will fire up along it. Dewpoints in the upper teens will combine with daytime highs in the mid–20’s to produce MUCAPE values as high as 2000J/kg ahead of the front. Shear will be marginal with only around 25–30kt of surface-to–500mb bulk shear and the vertical wind profile isn’t particularly favourable for severe weather. The cold front will be enough of a trigger, although it will be weaker than yesterday and not offer nearly as much forcing as it did then.
As a result, thunderstorms will likely fire up somewhere in the central or eastern Red River Valley and push into the Whiteshell and far SE Manitoba this afternoon. At this point it doesn’t look like there will be an organized severe weather threat, but we’ll be taking a look a little later this morning to assess whether or not the severe threat needs upgrading.
Other than the storms, the day will be pleasant. Before the cold front passes the Red River Valley will be under a relatively light southerly or southeasterly wind. It will be fairly humid and temperatures in the low 20’s until the passage of the front, after which westerly winds at 30–40km/h bring in much drier air. The afternoon sunshine should help our daytime high climb to around 25°C.
Temperatures will drop to around 14°C under clear skies and light winds tonight.
24°C / 13°C
Mainly cloudy with widespread showers
Tomorrow will be the least pleasant day of the next few. A strong upper-level low will slide across Southern Manitoba through the day, producing widespread showers underneath it. There may be a few isolated thunderstorms, but for the most part most areas in Southern Manitoba will be seeing a fairly wet day. Winds will generally be 20–30km/h through much of the day, shifting from southwesterly or westerly to northerly through the day and overnight.
Skies will begin to clear overnight as the temperature drops to around 13°C.
24°C / 13°C
Sunday will likely start off with some low cloud trapped in the boundary layer making for mixed to mostly cloudy skies. As the temperature rises through the morning, the clouds will gradually break up leading to a mainly sunny afternoon with some scattered clouds. Highs will be around the 24–25°C mark and temperatures will drop to around 13°C once again on Sunday night.
This pleasant weather will continue through the first half of next week. Another strong ridge is forecast to build into BC/Alberta, which will keep temperatures seasonal and the weather dry.
Full discretion: I’m writing this on Thursday evening, and still unsure on how much of Thursday night’s convective activity will survive to the Red River Valley. ↩
Seasonal highs in Winnipeg right now are around 26°C. Seasonal lows are around 13°C. ↩