Prairie Weather (Rural Roots Canada) – Storms continue to diminish, as heat takes over
Spring and early summer rains have produced mixed results across the prairies. While some fields were flooded out, others are prospering, including this canola field near Bentley, Alberta:
The Prairies are working through one more round of active weather before the pattern settles down. A broad upper trough sits over eastern Canada as a weak ridge builds across the western Prairies, and a weak low over far northern Alberta is tracking east along the northern edge of that ridge Thursday. This system still carries real punch in the near term, with a severe thunderstorm risk across northeastern Alberta and northern Saskatchewan, but behind it, expect a longer stretch of sunshine, warm weather, and lighter winds. Southern areas sit under the core of the ridge for much of the period, with highs reaching the upper 20s and low 30s, while central and northern regions fluctuate a bit more as the ridge expands and retreats.
Thursday
Peace Region
An air quality warning remains active for Grande Prairie as wildfire smoke lingers, though the low-pressure system tracking through may help douse some of the responsible fires overnight, and an easterly flow moves the remaining smoke out by Friday. The low is not going to produce a whole lot of rain in the Peace Region. Expect mainly isolated showers or a stray thunderstorm rather than anything widespread. Expect highs near 25 or 26 in the BC Peace, and 28 for Grande Prairie.
Alberta
Severe thunderstorms are likely in the warm sector of the low moving through northeastern Alberta, with fast-moving lines capable of strong wind gusts and severe hail the main concern. Edmonton likely stays just south of the severe potential, though a trigger along the cold front could bring storms as far south as the city. A heat warning has expanded north to include much of central Alberta, including Calgary and Edmonton, with highs in the low-to-mid 30s for three straight days. Elsewhere, highs will reach the high 20s. Southeastern Alberta could see a weak shortwave spark a storm in the late afternoon or evening, but widespread storm development in the area is not expected.
Saskatchewan
The surface low tracks into northern Saskatchewan this afternoon, triggering thunderstorms with severe hail and damaging wind gusts the primary threats. Central Saskatchewan and the area near Rosetown see hot temperatures build ahead of the front. Extreme heat is also moving into southern Saskatchewan today and is expected to last through the weekend, with the first heat warnings issued and more spreading east and north by the weekend. Highs in the south and near Rosetown will reach the low 30s, with the rest of the province experiencing the high 20s. A westerly flow developing later in the week could carry wildfire smoke from southern BC into the southwest, so an air quality warning is possible there too.
Manitoba
The warm front arching into northern Manitoba triggers convection through the afternoon and evening. A severe thunderstorm can’t be ruled out, with damaging wind the primary concern. Showers and storms continue overnight into Friday as the low tracks east, with rainfall in the 10 to 30 mm range, and locally 50 to 70 mm in the stronger storms. South of the lakes, across agricultural regions, it stays dry with highs reaching the high 20s.
Friday
Peace Region
Smoke clears out as the easterly flow takes hold, leaving a sunnier, warmer day behind. Highs reach the mid to high 20s, with dry conditions returning after Thursday’s smoke and shower risk. The disturbance that went through northern Alberta Thursday will track southeast toward north-central Manitoba, leaving the Peace Region with quiet, warm weather through the rest of the day.
Alberta
Southern Alberta still may see the chance of hit-and-miss thunderstorms in the afternoon, and a severe storm with hail and strong wind can’t be ruled out. The atmosphere will continue to be unstable, and if a storm is triggered, there will be plenty of fuel to help it develop. The image below shows the energy available for storm production in the late afternoon:
The greatest potential for afternoon storms Friday is the area between Calgary and Edmonton.
Across the south, and as far north as Calgary, expect highs in the low-to-mid 30s. Beyond today’s system, the broader pattern is trending toward a quieter, sunnier stretch for most of the province, with central regions settling into the mid-to-upper 20s.
Saskatchewan
Convection tracks in from Alberta through the afternoon and evening, with hail and wind the biggest concerns over the western grain belt. As the same disturbance crosses into central Saskatchewan, increasing cloud and a better chance of scattered showers and a few thunderstorms develop there too, though much of the province should stay dry. Storms continue overnight as a surface trough pushes into southern Manitoba by Saturday morning. Extreme heat continues to build across southern Saskatchewan, with Prince Albert calling for a multi-day heat event running through Monday, highs in the low 30s, and humidex values reaching the low 40s.
Manitoba
Overnight storms from Thursday continue into Friday morning, before reorganizing behind the departing low. As the disturbance reaches Manitoba later in the day, it taps into higher humidity, allowing showers and thunderstorms to become more widespread across central and southern Manitoba by evening. This isn’t expected to be a particularly strong system overall, but a few thunderstorms could become strong, depending on the exact track. Highs in southern Manitoba and the Interlake will come close to 30 degrees, and the storm threat won’t start to diminish until evening.
Saturday
Peace Region
The ridge that’s held over Alberta starts to slip, and a cooling trend begins. Highs will only reach the low 20s, with the chance of showers climbing overnight as the pattern shifts toward more active weather by Sunday. Saturday would be a good day to complete field work, as rain on Sunday will keep you indoors.
Alberta
An upper ridge attempts to rebuild across the province over the weekend, though additional weak disturbances continue riding along its northern edge with uncertain timing and strength. If they stay weak, expect plenty of sunshine and highs in the upper 20s to low 30s. Southern heat warning criteria likely persist through the day. Medicine Hat and Milk River have the potential to reach highs of 36 degrees.
Saskatchewan
The ridge tries to rebuild here too, and if the weekend disturbances stay weak, producing only scattered showers, most of the province enjoys a dry, sunny stretch with highs in the upper 20s to low 30s. The extreme heat event continues regardless. Humidex values in the 40 to 42°C range are possible in central Saskatchewan, a dangerous stretch for anyone working outdoors.
Manitoba
Most of Manitoba will reach the 28-30-degree range, as the ridge tries to reassert itself, with the heat and humidity continuing to build ahead of Sunday’s peak. Should the northern disturbances prove a bit stronger than expected, a little more cloud and an isolated shower or thunderstorm are possible, particularly toward the northern end of Lake Winnipeg, but confidence on that is low.
Sunday
Peace Region
Rainy weather returns to the Peace Region, with a few breaks in the midday. Highs will only get to the mid-to-high teens, a sharp changeover from the heat further south and east. This is the region’s best chance for meaningful rainfall since the smoke cleared out Friday. The map below shows rainfall expected by early evening, and while it’s not incredibly impressive, it is significant:
Alberta
Southern Alberta cools to the high 20s, with some lingering warmth pushing temperatures to the low 30s in some spots. Current indications suggest another weak system may bring scattered showers and a few thunderstorms to central and northern Alberta by Monday, while the south stays largely dry. The rainfall pattern is shown in the map above, and most areas will get 10 mm or less. The rain will have an impact on afternoon highs in the region, perhaps cooling the area to the mid-20s.
Saskatchewan
This is forecast to be the hottest, muggiest day of the stretch for central Saskatchewan, with Prince Albert expecting the low 30s and humidex near 40. The heat event continuing through Monday means little relief in the immediate outlook. Watch for heat stress in livestock and avoid unnecessary field work through the hottest part of the afternoon.
Manitoba
Winnipeg climbs to the low 30s with a mix of sun and cloud, the warmest day of the outlook for the province. Similar heat can be expected across southern Manitoba and the Interlake. That heat combined with lingering humidity keeps a thunderstorm threat alive, particularly toward evening as the next weak disturbance approaches from the west.
EVENT FORECASTS
Manitoba Threshermen’s Reunion and Stampede – July 23 to 26, Austin, Manitoba
July 23 – Sunny, breezy, high 30
July 24 – A mix of sun and cloud, wind gusting to 40 km/h, high 30
July 25 – Sunny, high 29
July 26 – Partly cloudy, chance of midday showers, chance of thundershowers, high 28
Medicine Hat Stampede – to July 25, Medicine Hat, Alberta
July 23 – Sunny with a few evening clouds, high 35
July 24 – Sunny, high 34
July 25 – Sunny, high 37
COMPARE: Prairie Weather This Week – July 20
