Prairie Weather (Rural Roots Canada) – Rain returns to dried-out fields in southern Alberta and Saskatchewan.

This is the week the pattern actually turns for the drought-stressed southern prairies of Alberta and Saskatchewan. An upper ridge that dominated July and kept southern Alberta and southern Saskatchewan hot and dry is breaking down. This gives way to a series of troughs swinging through from the Gulf of Alaska. That opens the door to real moisture for the region that needs it most, arriving first in the north and foothills early in the week before spreading southeast through the back half. This isn’t expected to fully erase the moisture deficit built up through July, but it’s the first real break the southwest has seen in weeks.

The map below shows accumulated rainfall totals expected until the evening of Sunday, August 16. And, for southern Alberta and southern Saskatchewan, a lot of rain is on the way:

Along with the wetter weather, temperatures will trend cooler than average across the southern Prairies for much of the week. The chart below indicates the switch to cooler weather. It indicates the probability of temperatures reaching 30 degrees from now until the evening of Sunday, August 15. It’s almost like there’s a wall at the border preventing heat from moving up from the US:

From the two maps above, it is clear we’re in for a period of wetter and cooler weather.

Here’s the outlook – day by day, and region by region:

Monday

Peace Region

Rain and thunderstorms are possible throughout the morning across the northern foothills east to Highway 2, extending into the Peace Region. After a possible midday break, rain moves back into the Peace alongside continued thunderstorm chances by afternoon. Between 5-10 mm of rain, at the most,  can be expected during the day. This is the leading edge of the moisture shift discussed above, and it’s welcome news if your soil moisture has been running short. With the wet weather, temperatures will be held to the mid-teens.

Alberta

Morning thunderstorms track from the northern foothills east toward the Saskatchewan boundary. Rain is expected throughout most of the day in central Alberta, moving into south-central regions in the afternoon. Thunderstorm chances will continue along the northern foothills corridor and expand into southern Alberta. If you’re in the south, this is the first sign of the pattern change reaching your area after a dry July, though it may take a few more days to add up to anything significant. Temperatures in south-central Alberta will stay in the mid-teens, but will rise to the low to mid-twenties in the south, where wet weather is not expected. Yet.

Saskatchewan

No specific threats are flagged for today, with the active weather concentrated in Alberta. That said, some of the Alberta showers may drift into west-central Saskatchewan by late afternoon. Harvesting of pulse crops in the southwest should be able to continue under generally dry conditions, though, again,  it’s worth watching Alberta’s system for any eastward drift. Highs across Saskatchewan should reach the low 20s, though closer to the mid-twenties near the U.S. border.

Manitoba

Quiet conditions hold in Manitoba with mainly sunny conditions, with the active pattern still confined to Alberta. The only rainfall anticipated in Manitoba Monday will be near the Hudson Bay shore. In agricultural regions across central and southern Manitoba, highs will be in the 20 to 22 degree range.

Tuesday

Peace Region

Rain continues to affect the region through the morning, with thunderstorm chances holding into the afternoon, mainly south of the Peace along the northern foothills corridor east to Highway 2. Northern portions of the Peace, including the town of Peace River, can expect sunshine. Where it rains, highs will remain in the teens, but 20 degrees or better are expected in drier, sunnier areas.

Alberta

Rain covers central Alberta through the morning, with thunderstorms possible across north-central Alberta, the Peace Region, and southern Alberta. By the afternoon, thunderstorm activity concentrates specifically near Edmonton and Waterton, alongside the ongoing foothills corridor threat. Two very different parts of the province, Edmonton in the central corridor and Waterton in the far south, both see storm chances today, so this looks like a broad, multi-cell pattern rather than one tracking system. Outside of Edmonton and Waterton, the thunderstorm chances are less, but rain is expected nevertheless. Higher elevation of terrain = higher amounts of rain. The foothills and eastern slopes of the Rockies can expect about 15 mm of rain Tuesday, with heavier localized amounts. The rain will keep high temperatures in the teens. In southeastern Alberta, where it will remain dry, expect highs in the 20 to 22 degree range.

Saskatchewan

It will be a rainy Tuesday in the southern half of Saskatchewan, though no serious thunderstorm threats are expected. The rainfall won’t be evenly distributed. Some areas can expect less than 10 mm on Tuesday, but closer to Saskatoon, amounts may exceed 15 mm. Further north, it will be a dry day across northern and north-central Saskatchewan. This wet weather will again pause any harvesting of peas and lentils, but the moisture will be welcome, given the dry conditions of the past few weeks. Across the province, highs will range from 18 to 22, with rain having localized cooling effects.

Manitoba

Conditions remain quiet in the morning, but rain moves in from southern Saskatchewan during the day. By afternoon, rainy weather will dominate southern Manitoba and the Interlake. The bulk of the rain will fall from the Trans Canada Highway and south, and some areas may receive up to 10 mm. In that region, highs will reach the mid-teens. It will be warmer to the north, where it will be sunnier and drier. Temperatures across central Manitoba should reach the low 20s.

Wednesday

Peace Region

The heaviest of the week’s Alberta-focused rain has largely shifted south and east by this point, so expect a comparatively quieter day here, though a few showers can’t be ruled out, especially in the afternoon.  Expect a cloudy sky with sunny breaks, and highs in the high teens or low 20s.

Alberta

Significant rainfall returns to southern Alberta on Wednesday, as shown in the map below:

Rain affects the Alberta foothills through the morning, with thunderstorms possible near Edmonton and Waterton again today. Afternoon rain continues along the foothills, with the heaviest rainfall expected south and southwest of Calgary, where totals could reach 50 mm between High River and Diamond Valley. This marks three straight days of at least some moisture reaching the province, a meaningful change after July’s dry stretch. With all the rainy weather, it will be a cool day, with highs of only 8 to 12 degrees over the foothills, and 17 to 19 degrees elsewhere.

Saskatchewan

Rain reaches central Saskatchewan Wednesday morning, with another area of rain forming in southern Saskatchewan between the Trans Canada Highway and the US border. In that southern area of rain, thunderstorms are possible. It’s a mixed blessing perhaps for producers. It will continue to stall the harvest of pulse crops, but it will bring badly needed moisture to a dry region. In between the two areas of rain, dry weather is expected – but not guaranteed – between Regina and Saskatoon. Highs in dry regions will reach the low 20s, but will be limited to the mid to high teens in those areas that get rain.

Manitoba

It will be a dry day across most of agricultural Manitoba, but afternoon showers will likely develop in the Interlake. If you’ve got hay or cereals still down in that area, plan early morning work rather than assuming a dry day.  South of Flin Flon and Thompson, temperatures will likely rise to the low 20s. To the north, highs will be in the 15 to 17 degree range.

Thursday

Peace Region

Another rainy day is expected in the BC and Alberta Peace region, with heavier amounts in the morning, slowly tapering off as the day goes on. Less than 10 mm can be expected during the day, just wet enough to continue postponing any fieldwork. Clouds will dominate, though there may be some sunny breaks toward the afternoon. Temperatures will be below average with afternoon highs reaching only the mid to high teens.

Alberta

Rain affects Alberta south of the Yellowhead Highway in both the morning and afternoon, with the foothills seeing the heaviest activity. This is shaping up as a wetter, more prolonged event than earlier in the week, concentrated squarely over the part of the province that needs it the most. Rainfall amounts of 30 to 40 mm can be expected from Calgary straight east to the Saskatchewan boundary. To the south of that line, rainfall will still be significant, but a bit less, in the 20-to-30 mm range. The rain will extend north beyond Edmonton, with the highest amounts falling west of Highway 2. And, as one might expect, with all the rain comes cooler weather, with highs ranging from single digits in the foothills to 11-to-14 degrees across the rest of Alberta.

Saskatchewan

Rain reaches western Saskatchewan through the midday and afternoon as the system continues its eastward push. If you’re harvesting in that part of the province, plan for a pause, though the moisture should be a net positive for any later-maturing fields or pastures still trying to recover from July’s heat.   That incoming moisture will suppress afternoon highs. West and north of Regina, highs will only make it to the 15- to 19-degree range. Eastern Saskatchewan could warm to the low 20s, but don’t count on it.

Manitoba

No specific threats are flagged for today, with the system’s main focus still to the west. The day will begin with sunshine across the province, with some clouds and perhaps a few spotty showers moving into southwestern Manitoba by the end of the day. Accumulations will be insignificant across agricultural areas. However, accumulations of 5-10 mm can be expected around Flin Flon and The Pas.

Friday

Peace Region

Quieter conditions return as high pressure rebuilds at the surface. If there is any rain in the Peace on Friday, it will be in the early morning and will clear out rapidly. By the afternoon, sunshine returns to the region. Whether fields will be dry enough to resume work is a bit uncertain, so monitor closely. If you can get onto the fields, the weather will co-operate, with pleasant highs near 19 or 20 degrees.

Alberta

Rain continues in the foothills, then tapers off elsewhere during the day as the main area of rain moves into Saskatchewan. This brings an end to the wet weather pattern, at least temporarily, though fields will likely be too wet to support heavy equipment. It means another day of rest for the combines that have been harvesting pulse cops near Medicine Hat. As the rain ends, the sky becomes mainly clear to partly cloudy. Despite the return of sunshine, the northerly flow ensures it stays cool with highs across most of the province in the 14- to 18-degree range.

Saskatchewan

Rain affects the province more broadly by afternoon, building on Thursday’s push into the west. Combined with Alberta’s rain, this is shaping up as the best two-day stretch of moisture the southwest grain belt has seen in weeks. Some impressive rainfall totals can be expected Friday in Saskatchewan, according to the map below:

With all that wet weather, temperatures will only reach the mid-teens in the afternoon.

Manitoba

As the map above shows, it will be a dry day in Manitoba, except for some areas adjacent to the Saskatchewan boundary. It will also be one of the warmest days of the week, with temperatures in the dry areas from south to north climbing into the 20 to 25 degree range. It would have been warmer were it not for the cloud that will thicken up during the course of the day.