Prairie Weather (Rural Roots Canada) – If you are reading this on Monday (as most do), and you’re in Alberta, chances are it’s going to snow, it is snowing, or it has snowed.   The first significant snowfall of the year for Alberta is well-timed.  It comes as the harvest has all but wrapped up across the three prairie provinces. And, as the soil has not yet frozen, some of the moisture from this snow will seep into the ground, and will be banked for next spring.   Most of Alberta, and parts of west central and northern Saskatchewan will experience Monday snow.   We’ll check out the rest of the week further below.

Canadian Drought Monitor

Some amazing news from the Canadian Drought Monitor – most of the agricultural land on the prairies is no longer in drought!    58% of the prairies’ agricultural landscape is neither abnormally dry nor in drought.   That’s a big improvement over recent weeks and months.   However, when non-agricultural land is factored in, 58 percent of the prairies is still considered dry or in drought.   While there was improvement across much of the prairies, central regions of Alberta remain stubbornly dry, and as shown in the map below,  pockets of drought remain between Edmonton and Calgary, and just west of Edmonton.

A lack of rain last week allowed farmers to bring in the remainder of the crop, though the harvest days were shortened by early morning frost and dew.

La Nina Update

La Nina is still on his way, with a 60 percent expectation to emerge between now and November, with its effects fully felt in January to March.    There are some changes, though, to the La Nina forecast for this winter.  The latest update from NOAA suggests this La Nina will be weak, and of short duration.   The chart below shows La Nina is now expected to end before the snow melts, with neutral conditions returning by spring.

This change toward a shorter, weaker La Nina, won’t have much of an impact on the expectation for higher than average precipitation and colder than average weather across the prairies through early 2025.    However, if La Nina ends early in the spring, it may lead to drier weather just before planting season.   It’s pure speculation at this point, but something to watch in the coming months.

This week’s forecast:

Monday:

Alberta

As mentioned, Monday will be a snow day across Alberta.   Though the amount of snow won’t be significant, it is the first snowfall of the year,  so it will be disruptive, especially on the roads and highways.    The snow is generated by a surface Low in western Saskatchewan, supported by a trough of low pressure in the upper atmosphere.   Snow amounts will vary, with perhaps 5-10 cm in south central Alberta, and in the northeastern part of the province.  there will be some pockets of heavier snow, with accumulations above 10 cm.    The snow may start in the midday, with the heaviest snowfalls occurring in the late afternoon and early evening.   This chart shows expected accumulations, according to Environment Canada’s RDPS model:

In addition to the snow, expect a reverse temperature trend.   The morning will be warmer than the afternoon.   It could be as warm as the double digits in much of southern Alberta at sunrise.  By the afternoon, especially in areas that get snow, temperatures will fall below freezing and continue to fall through the night.   On the animated map below, it’s clear to see how the cold air will march into Alberta during the day.    The map covers a 24 hour period between 6:00 am Monday and 6:00 am Tuesday.    Tuesday morning will be the coldest so far this season.

Saskatchewan

While a Low in eastern Saskatchewan produces the moisture that drops the snow in Alberta, southern Saskatchewan can expect a dry day.  It’s not until evening, as the low slides toward Lake Manitoba, that the moisture hose will turn on in Saskatchewan.   South of Saskatoon, expect rain Monday night, while snow will fall further north.  Before the rain begins, it will be very warm in southern Saskatchewan, with highs in the low 20s. (compare to Alberta, where temps will be in the 20s – Fahrenheit).    Those who are still working the fields will have plenty of time before the late day rain.

Manitoba

With all the meteorological mayhem happening to the west, most of Manitoba will have a dry day.  There will be some rain and snow north of the lakes, but within the Interlake, and in southern Manitoba, there won’t be a drop of rain or a flake of snow during the day.   It will be warm, with temperatures reaching the 20s south of the Trans Canada Highway.  Enjoy the day, because when the low arrives from the west on Tuesday, there will be a big change in Manitoba’s weather.  (see below).

Tuesday:

Alberta

Tuesday dries out, and by mid afternoon, sunshine will be abundant throughout the province.   It will be a dry day, but the cold air that arrived on Monday will stick around.   By noon, temperatures will still be close to 0, and in the south will only rise to highs of 8-10.  North of Calgary, it will be even colder, with highs only reaching the mid single digits at best.

Saskatchewan

The weather system that brought cold, snowy weather to Alberta Monday, moves into Saskatchewan Tuesday.  However, it will run into warm air, so most of the precipitation will be in the form of rain.   Expect that rain to fall across southern Saskatchewan first thing in the morning.   The Low producing the precipitation is, by this time, in Manitoba, but Saskatchewan will get the wrap-around rain until late afternoon, when the moisture moves to Manitoba.    Also wrapping around the Low is colder air.   Most of the moisture north of Saskatoon will fall in the form of snow, and some of the rain in the south could change over to snow in the early afternoon due to the invasion of the cooler air.   The sky will clear out in the evening and overnight.   During the entire day, temperatures will remain in the low single digits in the south, and a few degrees below freezing in the north.

Manitoba

In the interlake and south, the day will begin with rain, and north of the lakes, expect snow.   The rain and snow will intensify, peaking in the early afternoon.  The low pressure system crossing the province will be in Ontario by midday, but the wrap around moisture will carry on through the day.   Similar to what happened over the previous two days in Alberta and Saskatchewan (see above), cold air will funnel in from the north, but in southern Manitoba, it will likely stay warm enough to prevent the rain from turning to snow.   The weather event should be done by evening.   Temperatures will stay above zero in the south and in  the Interlake.   Way up north of Lynn Lake, temperatures could drop to -15 in the evening.

Wednesday:

Alberta

Another rather quiet day can be expected, and the northern and southern parts of Alberta will be mainly sunny.   However, a weak surface trough will produce some late afternoon rainfall in the vicinity of Lloydminster.  Amounts will be light.   A band of cloud will drape across Alberta’s midriff due to this weak system.  Underneath that cloud, temperatures will remain near zero, with 5-10 degree highs more likely in southern Alberta, and around the Edmonton area.

Saskatchewan

The day will start off mainly sunny with a light southwesterly wind.   As the day goes on, we’ll see cloud thickening up north of Saskatoon, and some thinner cloud coming into southern Saskatchewan from the southwest.    It will be dry, except for a few showers coming out of a weak system near Lloydminster.   South of the Trans Canada Highway, temperatures will peak between 10-15 degrees.  It will be about five degrees cooler through central Saskatchewan.

Manitoba

With the previous day’s system having moved on into Ontario, the weather will be dry Wednesday all across Manitoba.   In southern Manitoba, there will be a southwesterly wind, but it will be cool, with highs of 5-10 degrees.  In northern Manitoba, expect highs between 0 and 5.   No significant weather is expected.

Thursday:

Alberta

High pressure slowly building  in southern BC will force a westerly surface wind in Alberta, and that will keep us in dry weather.  It’ll be partly cloudy across most of the province, with seasonable temperatures.   Except for the far north, where highs will be between 0 and 5, temperatures across most of Alberta should reach the low double digits.  In southeastern Alberta, from Bassano to the US border, including Lethbridge, Raymond, Warner, and Milk River, temperatures will warm to the low teens.

Saskatchewan

A westerly wind will keep most agricultural regions dry, but there is a chance of some midday rain showers through central Saskatchewan.   The showers won’t last long, and accumulations won’t be meaningful.   In the far northern boreal forest, there will be snow through much of the day.   It will likely be heavy, wet snow, with temperatures near zero.  5-10 degree afternoon highs can be expected south of Prince Albert National Park to the US border, with no significant weather.

Manitoba

Most of Manitoba will be dry all day Thursday.   However, showers that develop in the midday in Saskatchewan will cross central Manitoba during the afternoon.   The rain will miss the agricultural regions of the south.  However, there will be considerable cloud cover through the day.   The cloud will clear out in the evening as the central Manitoba rain moves east. The wind will come out of the west, and there will be no significant weather events, as temperatures between the Interlake and North Dakota reach 5-10 degrees, with a pocket of warmer weather from Winnipeg and Portage La Prairie south to the US border.    Further north, highs in Manitoba will come in within a few degrees of zero.

Friday:

Alberta

After a frosty morning, with sub zero temperatures across the province,  it will warm up as the sun shines through the midday.   Toward late afternoon and evening,  chinook conditions will develop, including the familiar arch over the foothills in the south.   A large Low pressure system develops in the Gulf of Alaska, which will shoot Pacific air across BC, giving us chinook conditions in southern Alberta.    That means it’ll be dry and breezy east of the Rockies.   North of Edmonton, away from the effects of the late-day chinook, temperatures will peak near zero, despite the sunshine.  In the chinook zone, computer models show high temperatures hovering between 5 and 10.  That’s not especially warm for an October chinook, but the chinook’s late arrival will keep temperatures from climbing any further.   That said, chinooks are notorious for busting temperature forecasts, and that could very well happen here.    Windy, dry, and warm (maybe).

Saskatchewan

Dry air will continue to be pumped into Saskatchewan with a westerly flow.   Most of Saskatchewan can expect temperatures to rise to the low single digits, with highs of 5-10 expected south of Davidson and Melville to the US border. Otherwise, the sun will shine, and no significant weather is expected.

Manitoba

Daytime showers or rain are expected between the southern basin of Lake Winnipeg and the Ontario boundary.   Otherwise, southern Manitoba can expect a sunny Friday, and temperatures could rise as high as 10 degrees all the way to the northern shores of the lakes.  Further north, subzero temperatures are expected over the permafrost, where early morning snow will cross northern Manitoba from east to west, ending up in Hudson Bay by the end of the day.

Saturday:

Expect dry weather Saturday morning across all three provinces until the late afternoon, when snow will fall in northwestern Alberta.  The moisture will be flung into the area by a strong Low pressure system in the Gulf of Alaska.  Overnight and into Sunday morning, the snow will move toward northern Saskatchewan.   Otherwise the prairies will be dry on Saturday, with no moisture expected in the southern and central agricultural regions.  Expect sunshine, with bands of thin cloud crossing the prairies from west to east during the day.  In the south, it will be a warm day, with widespread highs of 5-10 degrees through the central prairies, but even warmer south of the Trans Canada highway in Saskatchewan and Manitoba.   There, expect highs in the low teens.  The warmest area on the prairies will be southern Alberta, with highs reaching the mid to high teens as far north as Edmonton.

Sunday:

The powerful Pacific low moves across Haida Gwaii and onto the mainland during the day,  and gives birth to a secondary low pressure system in the lee of the Rockies in southern Alberta.  This will create a cloudier day for most of Alberta, with partly cloudy conditions prevalent in southern Saskatchewan and southern Manitoba.   An area of mixed precipitation will develop in the Peace, but the rest of the prairies will stay dry.   The Alberta low pressure system will move east, with the potential to change prairie weather in a big way early next week, but we’ll have more on that in our regular update on Monday morning.   Early morning temperatures Sunday will remain above zero across Alberta and western Saskatchewan, but cloud drop as low as -15 in southeastern Saskatchewan and southwestern Manitoba.  Sunday will be a very warm day in Alberta, with temperatures potentially reaching 20 in the south.   The rest of Alberta, Saskatchewan, and Manitoba, can expect highs in the low to mid teens, except for the far north, where temperatures will peak near zero.

COMPARE TO LAST WEEK’S FORECAST: Prairie Weather This Week – Oct 14