Prairie Weather (Rural Roots Canada) – La Nina update, Drought Monitor, Chinooks, Blizzards.
It has been a cold, snowy December across most of the prairies, and for the most part, it was expected. La Nina conditions have established, bringing cold weather and plenty of precipitation to Western Canada. BC has been hit by huge rainfalls, and the prairies are getting some very welcome snowfall, and some less-than-welcome Arctic air. La Nina is finally performing as expected. and it’s likely here for the rest of the winter. The latest La Nina advisory from the US National Oceanic and Atmospheric Administration expects a shift away from La Nina conditions toward the end of the January-March three month period.
If all goes as expected, we will transition out of La Nina into neutral conditions (neither La Nina nor El Nino) in the spring. For Western Canada, that means a return to more “normal” conditions. but with the potential for a lingering cooling and wet influence from the preceding weak La Nina in early spring.
And this week, La Nina will produce snow, and plenty of it across Western Canada. In agricultural regions, the heaviest snowfall is expected along the Trans Canada Highway, though amounts elsewhere in Saskatchewan and Manitoba will be significant. The next two maps show snowfall expected up until Sunday night at midnight.
Considerable snow will fall in Alberta, except for areas south of highway 3, where snowfall will be minimal to non-existent.
The map above shows 40 to 45 cm for the Peace Region, which would be very welcome in light of the exceptional drought in the area. An update to the Canadian Drought Monitor has been released, and the Peace has the worst drought in the country, so the snow outlook for this week is encouraging:
Over the past month, changes to drought conditions have been minor across the prairies. Extreme and severe drought no longer applies to the Lloydminster region, but extreme drought remains between Calgary and Edmonton. Drought conditions slightly worsened in southwestern and central Saskatchewan. In Manitoba, precipitation in November was below average, but drought conditions didn’t change significantly, due to the wet conditions left behind by earlier rainfall.
Click here for the full drought monitor update.
A strong Arctic air mass remains bottled up over the Canadian Arctic, but the focus shifts to the Pacific. A strong low pressure system moving into the Gulf of Alaska is forcing energy inland, priming the jet stream to spin up a series of Alberta Clippers this week. This track will repeatedly bring a mix of milder Pacific air crashing against the cold Arctic dome, resulting in two distinct, impactful snowfall events for the central and eastern Prairies.
Monday
Alberta
Warm and windy weather is expected in southern Alberta. Cold and snowy conditions are anticipated for the north. A low pressure system develops in northern Alberta. That will provide snow for northern regions, and because the low will draw up some mild air from the south, there is a chance of a mix of rain and snow near Lesser Slave Lake during the late morning, changing to freezing rain in the early afternoon. The dividing line between the cold northern air mass, and the warmth to the south will be just north of Highway 16. The map below shows temperatures expected at 5:00 pm Monday:
Saskatchewan and Manitoba
Some of the warmer chinook air will move into southern Saskatchewan, and temperatures will rise above the melting point. The clipper system forming in Alberta will begin to track eastward across central and northern Saskatchewan, producing some light snow in the north. There is a risk of blowing snow as the clipper gets closer late in the day. In Manitoba, there will be lingering cold air from the weekend, but it will moderate somewhat. In the northern and central regions of Manitoba, expect light snow as an Arctic front passes through the area. The map below shows expected early evening temperatures for Monday:
Tuesday
Alberta
The clipper system that brought snow to northern Alberta Monday moves rapidly into Saskatchewan and Manitoba. Colder air begins to settle back in behind the system. Expect a mix of sun and cloud for the south and central regions. South of the Trans Canada Highway, it will be another day of above zero temperatures. Between Highways 1 and 16, expect highs near -5. Further north, highs will range from -15 to -25, as Arctic high pressure brings down temperatures. It will be what’s known as a “dirty” high, which means small impulses will be allowed in to spread light snow across most of northern Alberta.
Saskatchewan
The first potent Clipper begins to track east across central regions (north of the main agriculture belt). A swath of 10 to 20 cm of snow is possible for areas north of the Yellowhead Highway. The Clipper will draw warm air up from the south, and the Saskatoon area could see a mix of rain and snow. Rain is even possible southwest of Saskatoon in the early morning, rapidly moving east into Manitoba by the afternoon. Warmer air temporarily pushes highs near 0 in the south, but cold air will be drawn back in after the Clipper passes. In the afternoon, temperatures across Saskatchewan will again fall below zero. North of the Yellowhead highway, temperatures will fall to negative double digit values.
Manitoba
The Alberta clipper rolls through southern Manitoba during the day, bringing snow to the region. Rare December rain can’t be ruled out south of the lakes, as morning temperatures will climb above zero. As the day goes on, and the clipper moves into Ontario, afternoon temperatures in southern Manitoba will quickly plunge back down to near -15, as the sky clears toward evening. As an example, Brandon’s early morning temperature will be around +4. By evening, it will have cooled off to -12ish. North of the lakes, expect temperatures in the -20s and -30s.
Wednesday
Alberta
Yet another Alberta clipper forms, somewhere in southwestern Alberta. And that will again bring warm weather to the southern part of the province, with snow in central and northern regions. South of the Trans Canada highway, expect little to no precipitation, and if anything happens, it could be in the form of brief, light rain. A narrow band of heavier snow could from along Highway 1 from Calgary east to Saskatoon. The potential is there for about 20 cm of snow. Travelers will want to check road conditions and weather warnings before heading east of Calgary on Wednesday. The band of heavier snow will be very narrow, but lighter snow will fall through day to the northwest through Edmonton and as far as Peace River.
Saskatchewan
It will be a snowy day in Saskatchewan, particularly south of Saskatoon. In the north, arctic high pressure will keep the sky clear and the weather cold. To the south, a clipper in Alberta will spread snow into southern Saskatchewan with around 30 cm possible along the Trans Canada Highway corridor. The snow will continue through the day and into the evening, disrupting travel. There is the potential for strong wind causing blowing and drifting snow. While not as likely, the chance of blizzard conditions is not zero. Motorists should check weather warnings and road conditions before heading out. Better yet, it might be wise just to postpone travel in southern Saskatchewan on Wednesday.
Manitoba
As another clipper approaches, cloud cover increases rapidly early in the day, with potentially intense snowfall beginning across southern Manitoba through most of the day. South of the lakes, expect 20 to 30 cm of snow, with a strong northerly wind creating adverse travel conditions. Temperatures across most of the south will remain near -10 or below, and wind chill will be significant. Travel in southern Manitoba Wednesday should be postponed, but for those who have no choice but to travel, you will want to check weather warnings and road conditions before leaving. The weather in northern Manitoba will be less eventful as Arctic high pressure keeps the storms to the south. It will be cold, though, with highs across most of northern Manitoba near -30.
Thursday
Alberta
Other than some light snow in the Peace Region, it will be a mainly sunny and frigid day in Alberta, north of the Trans Canada highway. Temperatures from south central to northern Alberta are not likely to climb above -10. The Edmonton area can expect -18, and to the north, highs will remain below -20. There are some indications that chinook conditions are possible by the end of the day in southwestern Alberta, but there is a lot of uncertainty. If it happens, temperatures south of Claresholm and Lethbridge could climb above the melting point. Quite often, though, if a chinook doesn’t set up before sunset, it may not kick in until the next morning.
Saskatchewan
As the clipper moves out, high pressure moves in, and the Saskatchewan sky becomes sunny. It’s an arctic high, straight out of the north, and it will bring temperatures in the -20s to most of the province. There is a chance a chinook will set up over Alberta in the afternoon, and bring warmer weather to southwestern Saskatchewan. Highs might climb to -10 in southwestern Saskatchewan if this happens, but there is a lot of uncertainty. Because of the sunshine across most of the province, and the potential for a drying westerly wind in the south, significant snow is not expected anywhere in Saskatchewan on Thursday.
Manitoba
COLD! Lingering snow from the previous day will continue in the early morning across southern Manitoba. By midday, the snow moves east, and arctic high pressure takes over. That will clear out the sky, but it will also draw bitterly cold air into the province. Highs across Manitoba from north to south will range from -25 to -30. And with a brisk northerly wind, wind chills will be in the -40s, creating a high risk of stress to livestock. That same wind may also kick snow up off the ground, reducing visibility on the roads. Though snow will no longer be falling from the sky by the afternoon, blizzard conditions are possible due solely to the wind, the snow, and the blowing snow.
Friday
Alberta and Saskatchewan
Both provinces will have similar temperature profiles Friday. Chinook conditions will bring melting temperatures to southern Alberta and southern Saskatchewan during the morning and midday. A cold front brings that to an end in the afternoon, and temperatures in the area will fall back below the freezing point. Most areas south of the Trans Canada highway will experience this. To the north, temperatures in central Alberta and Saskatchewan will range from -10 to -15, and in northern regions. it will remain quite cold with highs in the -20s,, and wind chills in the -30s. Light snow, less than 5 cm, may fall along the Yellowhead highway through Saskatchewan.
Manitoba
A band of snow will move across southern Manitoba Friday. The snow will be light, and will move rapidly from west to east. The sky should clear out behind it. Northern Manitoba will be cloudy throughout the day. Temperatures in the Interlake and southern Manitoba will reach the minus teens, with highs in the -20s in northern regions.
Saturday and Sunday
Alberta, Saskatchewan, Manitoba
There won’t be a lot of snow over the weekend across the prairies. Northern Alberta is likely to see light snow both Saturday and Sunday. Central Saskatchewan may also endure some very light snow on Sunday. Otherwise, a dry pattern will set up over the three provinces. There is still no relief from the cold, with highs across all three provinces in the minus teens and minus 20s. Saturday could bring chinook conditions to southern Alberta again, but confidence is low. We’ll update this site with fresh information on Thursday.
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