Prairie Weather (Rural Roots Canada) – Dry weather ahead. Harvest: good. Soil Moisture: not so good.
Across the prairies, south of the Yellowhead highway, expect another week of dry weather, as farmers rush the harvest to completion. Time has become critical, as patchy frost has appeared in many areas, and will become more widespread from here on in, especially during clear nights, due to radiative cooling.
Frost Risk Oct 6-12
Alberta: cool nights expected, frost risk Monday morning.
Saskatchewan: higher probability of frost nights Monday morning, then toward Oct 8–10.
Manitoba: isolated subzero lows possible in sheltered locations by mid-week.
Frost has reached Ted Sherring’s farm near Carbon, Alberta:
As of Sunday morning, October 5, Ted had about 1200 acres of wheat left. Once that’s harvested, he’s done. According to most recent crop reports, 89 percent of Alberta’s harvest is complete, 84 percent in Saskatchewan, and 72 percent in Manitoba.
As mentioned, the weather will be harvest-friendly this week across the southern prairies. Toward the end of the week is where things become quite uncertain, and confidence is low.
Spring and fall are the shoulder seasons, the two times of year when the weather is most difficult to forecast. So, this week’s outlook comes with a higher than normal level of uncertainty. We will, as usual, provide an update here at Rural Roots Canada on Thursday, with a more confident outlook on the coming weekend.
The map below shows expected precipitation up until midnight Sunday night, Oct.12:
The map above indicates a large area of southern Saskatchewan and central Alberta may go through the week wtihout a single drop of rain. The heavy rain indicated for southeastern Manitoba will occur mainly in the early part of the week. Rain is also expected in southern Alberta, south of highway 3. Higher elevation snow can’t be ruled out.
Snow fell on the weekend in the southwestern Alberta foothills and in Waterton Park. 4 cm was reported by the morning of Sunday, October 5.
Monday
Map of expected temperatures near sunrise Monday morning. Anywhere shaded blue is at risk of frost:
Alberta
A few midday rain showers are expected near Grande Prairie, but for most of Alberta, it will be a dry day. Excellent harvest weather, though concerns over soil moisture will increase everywhere, but particularly in the Palliser Triangle. As the map above shows, there will be a risk of frost in Alberta’s southern and northern regions. Highs in the south will be near the seasonal average – low to mid teens. In central regions, expect highs of 9-11 degrees. Northern Alberta will be 4 or 5 degrees colder than average, with highs in the low to mid single digits.
Saskatchewan
The week will start warm and dry in southern Saskatchewan, marking a continuation of ideal harvest weather. In the north, however, snow will fall early in the morning, with rain the forested north-central regions. That moisture will move into central and northern Manitoba by the end of the day, with high pressure taking over to clear the sky. In the south, as the above map shows, the main risk is frost. In many areas south of the Trans-Canada highway, a killing frost is probable. During the day, temperatures will climb to the low double digits in southern Saskatchewan. In the north, it will remain cool after the rain and snow leave, so highs will only reach the single digits.
Manitoba
While rain and snow move into central and northern Manitoba during the day, it wil be a very favourable harvest day in southern Manitoba. It will be cool, however, with most areas only reaching the high single or low double digits.
Tuesday
Alberta
A southerly wind and a clear sky will provide sunny, dry weather to most of the province for most of the day. In the afternoon, some cloud will move into northwestern regions, including the Peace and Grand Prairie areas, and there may be a few showers in the northern foothills. A drying southerly wind will be beneficial to the harvest, but will continue to increase the soil moisture deficit. High temperatures will reach the mid teens, which is 5-10 degrees above average.
Saskatchewan
A very cold morning is expected across Saskatchewan, and frost is possible across most of the province, as the sky will be clear, allowing whatever heat there is near the surface to escape into the high atmosphere. Temperatures will fall below zero across the eastern 2/3rds of the province, with less of a frost risk on the western side. The sky will stay clear during the day, and in the afternoon sun, highs will reach the mid teens across southern and central regions.
Manitoba
A southerly wind and a sunny sky will provide another excellent harvest day. However, it will be a few degrees cooler than average, with highs falling a bit below 10 degrees. The latest Manitoba crop report indicates 72 percent of the harvest has been completed, and with Tuesday’s dry weather, considerable progress is expected as farmers rush to completion, trying to beat frost, snow, and other incoming adverse conditions.
Wednesday
Alberta
A surface low pressure system in the Northwest Territories will drag a cold front across central Alberta Wednesday morning. This will produce a band of rain that will cut across central Alberta in a SW to NE line between Jasper and Cold Lake. The front will continue to slump southward, but the rain will taper off everywhere except the west central foothills and mountains. Higher elevations will get snow. This may interrupt harvesting operations in central Alberta. In the southern and Peace Regions, it’s expected to stay dry. Double digit high temperatures are expected in most of Alberta, close to the seasonal average.
Saskatchewan
Agricultural regions in Saskatchewan will be dry on Wednesday, though there will be rain in the northern forests associated with a low in the Northwest Territories. The wind will come from the south early in the day, becoming more variable in the afternoon. The wind, along with temperatures in the mid to high teens will contribute to more drying, which, again is beneficial for the harvest, but detrimental to soil moisture levels.
Manitoba
It will be a warm day across Manitoba, with double digit highs, even well into northern regions, and with lots of sunshine and a southerly wind, progress will be made in a province where farmers have a lot of catching up to do.
Thursday
Alberta, Saskatchewan, and Manitoba
There are no weather related concerns for any of the three prairie provinces on Thursday, as s surface ridge of high pressure dominates the region. The 1023 mb high will be centred over southwestern Saskatchewan, and will provide sunshine to all three provinces during the day. Highs across the prairies will range from 11-15 degrees. At this time of year, when a sky clears out like this, frost is a real risk in the early morning. Not this time, except in central Alberta, where temperatures could drop slightly below the freezing point. Temperatures in Manitoba, Saskatchewan, and northern and southern Alberta should stay on the plus side early Thursday morning.
Friday
***Forecast confidence begins to drop, as computer models are not unanimous with their forecasts through the weekend.***
Alberta and Saskatchewan
The ridge of high pressure centred over Saskatchewan Thursday will move eastward, but it’s influence remains. Friday will be sunny and warm in Alberta and Saskatchewan, with dry weather and highs reaching the high teens. Near Lethbridge, in southern Alberta, there is a good chance some locations will reach 20. Frost is possible early in the morning in southeastern Saskatchewan.
Manitoba
Dry, sunny weather will also continue in Manitoba Friday, though it will be a bit cooler than its neighbors to the west. Highs will range from 10 to 15 degrees across the province.
Saturday and Sunday
There is very low confidence in the weekend forecast. We are reluctant here to talk about forecast models. Models are tools, not forecasts, and it’s up to human forecasters to take these tools and use them to build a forecast they can call their own. When you ask a carpenter to make a coffee table, it’s the table you want, not the tools the carpenter used to make it. Same thing with weather – you want the forecast, not the models. Forecasting by only quoting models is lazy.
Usually.
The above rant is a preface to the rest of this post. Below you will see three animated maps. They are maps showing what the models expect for weekend weather. You will see three different solutions. When this happens….when the models are not unanimous, it’s much more difficult for a forecaster to produce a forecast – especially when the target date is 6 or 7 days off in the distance.
Here’s the Canadian GDPS model:
Here’s the American GFS model:
And, the European ECMWF model:
As you can see from the Pivotal Weather maps above, we have three vastly different solutions for the weekend forecast. When models are rather close, we can create a blend, with reasonable confidence the outcome will be a more or less reliable forecast. But, when they are so different as they are here, there is much more uncertainty.
So, please check Rural Roots Canada again Thursday, when we’ll have better quality data, and a much better chance at providing a high quality weekend weather forecast.
