Prairie Weather (Rural Roots Canada) – Strong storms through Friday, and then it’s going to get hot.
The work week ends with more active and hazardous weather across the prairies. Hailstorms and tornadoes have brought havoc to the prairies over the past few days, and it’s not quite over yet. When it ends this weekend, prepare for intense heat!
An upper ridge builds fully through the weekend, and with it comes the most significant heat event of the growing season so far. Saskatoon reaches 31 degrees Saturday and 30 on Sunday. Winnipeg climbs to 33 Saturday and 37 Sunday, with humidex values approaching 45. The Peace Region and most of Alberta sit on the cooler, western side of the ridge and see clearing conditions rather than extreme heat, but southern Saskatchewan and southern Manitoba are squarely under the hottest air.
For Saskatchewan producers, the heat arrives at a sensitive time. Canola province-wide is currently rated 22 per cent excellent and 67 per cent good — a solid position — but crops in the east are running seven to ten days behind normal development after a cool, wet start to summer. That lag means more canola will be at or approaching flowering right as temperatures peak. Canola at full flower is vulnerable to blossom blast when air temperatures consistently exceed 29°C, and Sunday’s forecast does that by a wide margin across southern areas.
In terms of moisture, the prairies are set up well for a coming spell of hot dry weather. The map below shows very healthy rainfall accumulations over the past 60 days, with the exceptions of the Peace Region and southern Manitoba east of the Red River, which has more forests than farms:
Thursday
Peace Region
Wind is the main story across the Peace Region today, reaching speeds of 40 km/h, gusting to 60. High temperatures will reach the high teens or low 20s. Spraying is out of the question under those winds. Significant precipitation is not expected in the Peace on Thursday, which makes it a bit of a shame that wind will prevent some fieldwork.
Alberta
Thursday is another active and hazardous weather day across Alberta. Thunderstorms are likely this afternoon and early this evening, and some could become severe, capable of producing strong wind gusts, large hail and heavy rain. Wednesday saw severe weather hit parts of Alberta with large hail, and the setup today is similar. A few supercells could develop east of Calgary and track into southern Saskatchewan during the late afternoon and evening.
A low will develop around Calgary, likely just south of the city, bringing moist air into the foothills and a bulging dryline through the Trans-Canada corridor. Storm clouds are expected to form, but whether strong winds aloft tear the storms apart or actually support the development of supercell thunderstorms remains to be seen. Should severe storms develop, expect large hail and the possibility of tornadoes east of Calgary.
Though the weather will be much less hazardous in central and northern Alberta, a thunderstorm risk develops in the late afternoon. Rainfall amounts will be minimal overall.
A weather system brings precipitation to northern Alberta from Cold Lake to Slave Lake, and to the northwestern corner of the province in the Hay River Basin, through Thursday and Saturday. Generally 15 to 25 mm is expected, with locally higher amounts up to 60 mm possible in some areas. This is significant for producers still managing saturated conditions in the northwest.
Saskatchewan
The severe weather threat focus shifts to the Saskatchewan-Manitoba border region today, though significant instability covers a wide area. Multicell storms are expected; supercell storms are possible. Large hail will be the main threat with the more organized storms, which will move slowly, promoting heavy rainfall. A tornado or two cannot be ruled out. This will be a day to pay close attention to Watches and Warnings from Environment Canada.
With Saskatchewan canola running seven to ten days behind normal in eastern areas due to the cool, wet start to summer, the last thing the crop needs at this stage is a direct hail hit. If we can get through the next couple of days, some badly needed heat units will start to accumulate (see below).
Wildfire smoke from northern Manitoba fires continues, and air quality remains an issue in northern Saskatchewan.
Manitoba
Storms Thursday morning in western Manitoba will fade before more thunderstorms are expected to develop in the late afternoon, with the potential to be severe.
In southwestern Saskatchewan and spreading into Manitoba, the thunderstorm threat is serious. This is occurring in an area where flooding has washed out several roads. The image below shows Highway 10 near Pine River:
Several roads and highways remain closed in Manitoba’s Parkland Region, and in the Interlake.
Highs in southern Manitoba will reach the mid to high 20s, but it will be particularly humid. Moisture in the lower levels of the atmosphere is not something that is lacking lately, and that paired with rising temperatures will make for a volatile afternoon.
Hail damage to canola at this stage — whether buds are forming or crops are already at early flower — can cause significant yield loss. If you have canola approaching flowering in southwestern Manitoba, this storm threat is your top concern today.
Friday
Peace Region
A transition day. Showers linger early before the system moves through. Expect a 30 per cent chance of showers in the morning, clearing by afternoon as the ridge begins to move in. Highs recover to the low twenties. There remains a chance of isolated, non-severe thunderstorms in the afternoon. Light winds and fairly clear skies overnight will bring back the chance of fog and mist forming early Friday morning. If you’re moving equipment early Friday, take the fog risk into account, as visibility in lower elevations can drop quickly.
Alberta
Friday brings continued shower and thunderstorm risk in central and northern Alberta, similar to Thursday. Rainfall amounts won’t be huge, perhaps reaching 5-10 mm at the most. Central and northern Alberta producers should expect another non-working day. The clearing trend that sets up for the weekend applies more strongly to southern Alberta, where drying begins Friday afternoon.
For northern Alberta, including the Cold Lake to Slave Lake corridor, rain continues Friday. Amounts through the event may approach or exceed 25 mm in spots. Wet soils across the northwest are going to stay wet through the weekend.
Through central and northern Alberta, expect highs in the low 20s. In southern Alberta, it will be warmer, with highs in the high 20s, or even the low 30s in the southeast.
Saskatchewan
The morning carries residual severe weather risks near the Manitoba border as Thursday’s system exits. For most of Saskatchewan, Friday is a transition day. It will be somewhat unsettled through the morning, followed by a gradual improvement through the afternoon as the ridge advances from the west. Storms are likely to form in central Saskatchewan in the late afternoon and early evening, generated by local convection. Some of the storms may produce some significant downpours.
Expect temperatures to warm to the high 20s south of the Yellowhead Highway, and the low 20s to the north.
The main pest concern for canola this year is cabbage seedpod weevil, which is starting to appear in several southern and central regions.
Manitoba
Thursday’s organized storm complex arrives in western Manitoba before sunrise Friday morning, bringing the severe weather threat to the province. The morning is the highest-risk period. After that, the province transitions as the low tracks into northern Manitoba and the warm sector expands southward. Highs will get close to 30, while humidex values will produce uncomfortable warmth. Heat warnings could be in place Friday.
Friday ends with a dramatic shift in character. The heat event that defines the weekend gets underway.
Saturday
Peace Region
The ridge establishes and strengthens as we go into a period of dry, warm weather. Saturday brings a mix of sun and cloud with highs in the low twenties for the Peace Region. Saturday shapes up as a reasonable day to get back in the field for scouting and any pending spray work. Wind gusts will be lighter, and the shower risk is minimal, though not zero.
Alberta
A clearing trend delivers a much better day across southern and central Alberta. Drier and warmer weather should begin arriving as high pressure starts to strengthen across the province. Highs in the low-to-mid twenties for central Alberta, warmer in the south. Brooks, Milk River, and Medicine Hat are likely to reach the low 30s. The atmosphere remains a bit unstable, though, so afternoon showers and storms can’t be ruled out in central and northern Alberta. Southern Alberta should stay dry. This is your window to get equipment back in the field, assess any storm damage from earlier in the week, and advance any remaining spray work. The severe weather pattern that dominated Thursday and Friday has moved east.
Saskatchewan
Big heat arrives Saturday. A long-duration heat event is expected over much of southern Saskatchewan beginning Friday afternoon, lasting well into next week. Temperatures will climb to the mid-30s by the end of the weekend. Conditions will be particularly muggy this weekend, especially in regions along and south of the Trans-Canada Highway, with humidex values in the high 30s on Saturday.
For canola, this heat lands at a critical time. Saskatchewan canola is currently rated 22 per cent excellent and 67 per cent good. That’s a solid rating, but crops are already running seven to ten days behind normal in eastern areas.
Heat warnings are expected to be issued. Livestock need water access and shade. This is not a day for long-haul cattle transportation.
Manitoba
Saturday brings temperatures into the low 30s across southern Manitoba. It will be the warmest day of the spring and early summer so far, by a significant margin. Thunderstorms spread across agricultural Manitoba Saturday afternoon. The afternoon storm threat is real but less organized than Friday.
Scout any storm damage from Thursday and Friday’s events in the morning before the afternoon heat and potential convection arrive. Canola at the bud and early flower stage is your priority field to check, as hail bruising and stem damage may not be immediately obvious. The combination of physical storm damage plus incoming heat stress is your biggest crop risk this weekend.
Sunday
Peace Region
Weaker weather returns to the Peace on Sunday as a surface low-pressure system develops in the region. Showers should begin in the morning, intensifying to rain in the afternoon. Thunderstorms can’t be ruled out. The wet weather will limit temperatures, with highs expected to stay in the teens. The map below shows rainfall amounts expected Sunday:
Alberta
A clean, warm Sunday for the southern half of the province. Southern Alberta reaches the mid-twenties under sunny skies. However, as the map above shows, rain returns to central and northern Alberta, thanks to a rapidly developing low-pressure system in northwestern Alberta. The heaviest rainfall will be near the centre of the Low, but the rain will be widespread across the northern and north-central portions of the province. Temperatures there will only reach the mid-teens. In southern Alberta, where it will be drier, expect highs in the mid 20s. In southeastern Alberta, it will be hot, with temperatures climbing into the mid 3os.
Saskatchewan
Sunday brings humidex values near 40 for regions along and south of the Trans-Canada Highway. Temperatures, without factoring in the humidity, will reach the mid-30s in southern Saskatchewan.
Heat stress on canola at flowering is the dominant agricultural concern. Canola that is between 20 and 50 per cent flowering is in its highest-risk window — pollen viability drops and pod set declines when air temperatures are consistently above 29 degrees. Your main tools at this stage are limited: you can’t spray anything to mitigate heat stress, and irrigation is not widely available across the province.
Heat warnings are expected. Anyone working outdoors needs to plan for peak heat between 1 and 5 p.m. Drink water, take breaks, and do not leave people or animals in vehicles.
Manitoba
Winnipeg reaches 37 degrees Sunday with humidex values in the 40s. Overnight lows stay at 25°C. This is genuine, dangerous heat. People should watch for signs of heat exhaustion and heat stroke, as they can be life-threatening.
For agriculture, Sunday is a day to work early or not at all in the field. Get your work done before 10 a.m. Canola approaching or at flowering across the southern half of the province faces the same risks as in Saskatchewan. Livestock producers need to ensure adequate water supply.
The heat event does not end Sunday. Temperature and humidex values will ease slightly early next week, but daytime highs will remain in the high 20s to low 30s range for most of the week. The full impact of this event on crops at sensitive growth stages will take time to assess.
