Prairie Weather (Rural Roots Canada) – It’ll be mild until the weekend, then…..Yikes!

As mentioned in last Thursday’s midweek update, La Nina has arrived.  It was officially declared on January 9th, and is expected to persist for a few weeks, maybe into April.  The expectation is for La Nina to remain weak.    Prairie weather characteristics of La Nina events include colder than average weather, with above average snowfall.  It’s a weak La Nina, and no specific forecasts can be made, but for the next two or three months, it’s best to be prepared for cold, sometimes snowy weather.   And, just to give you a hint of the cold air that’s likely on its way, this is a map showing expected temperatures in the early morning of Monday January 20.    It’s a long way out, and this is not a specific forecast, but it does show temperatures as low as -30 C as far south as the mountains of Utah and Colorado, along with southern Saskatchewan.

prairie weather
Courtesy: ECCC

You may be looking at this and saying to yourself….”What? Cold in January?  Who knew?”   And, you’re not wrong.   Parts of the prairies, particularly Saskatchewan, have dealt with numerous extreme cold warnings so far this season, and for those areas, this doesn’t represent much of a change.   The point of the above map is just to show the effects La Nina could have on us for the next couple of months.

The other aspect of La Nina conditions is above average snowfall.   Below is a map of accumulated snow in the same time frame.   This shows the cold air associated with the above map, is due to Arctic high pressure, and a dry air mass.   So, in the snowfall map below, there is nothing that really correlates with the expectations of La Nina.  Except for parts of northern Alberta and Waterton Park, snowfall accumulations will be relatively light this week.

prairie weather
Courtesy: ECCC

Let’s dive into the where and when:

Monday

Alberta

By mid-morning, any of the snow lingering along the Saskatchewan boundary will have moved east, leaving behind a partially clearing sky.   A westerly wind develops across the province,  drawing in warm, dry air from the west.   Highs across the province will be near or slightly above zero, with the potential to reach high single digits just west of highway 2 between Red Deer and Edmonton.  Along the Saskatchewan boundary, it will be cooler,  but still above average, with highs between 0 and -5.

Saskatchewan

Unlike Alberta, much of Saskatchewan will be neither warm nor dry.   Mild air from the west will bump up against Arctic air in southern Manitoba.   Saskatchewan is the battleground, so expect some snow in a north-south line over the western half of Saskatchewan.   The mild Pacific air should reach as far east as Highway 11, and temperatures will rise to near 0.   East of highway 11 is the Arctic air mass, with highs only from -15 to -20.  Because of this sharp temperature difference, expect windy conditions across central Saskatchewan Monday.

Manitoba

All across Manitoba it will be cold, unlikely to rise above -15 anywhere.   Manitoba remains under the influence of an Arctic high which will travel along the western part of the province from north to south throughout the day.  The cold weather is being drawn in on the east side of the low, flooding Manitoba with cold air.   Clear, though.   Expect to see plenty of sunshine Monday, with weather similar to what we see in this highway camera photo from Sunday afternoon at the traffic circle at highways 6 and 236:

prairie weather
Courtesy: Manitoba511

Tuesday

Alberta

The warm westerly wind continues across Alberta throughout the day.   With a tight pressure gradient in central and northern Alberta, the  wind could be particularly strong, especially north of Edmonton.   In the south, the westerlies will warm the air, and the sunshine will lead to a further deterioration of an already thin snowpack.   There isn’t much snow in the south, as seen in this highway camera at Barnwell on Sunday afternoon:

prairie weather
Courtesy: AMA Road Reports

Temperatures will again rise above zero in most of Alberta on Tuesday, but the windier area in central and northern regions could warm as high as 10 degrees.   The warmest weather can be expected from Edmonton northwest to the Peace Region.

Saskatchewan

The mild Pacific air slowly works it s way east, and most of Saskatchewan will warm to somewhere between 0 and -10 Tuesday afternoon.   The mild air is still bumping up against a much colder air mass at the Manitoba boundary, and where the two air masses meet,  it could become quite windy.   However, there won’t be much snow.  Light snow is possible early in the day in southeast Saskatchewan, but it will quickly taper off before sunset.

Manitoba

The warm air from the west still hasn’t found its way into Manitoba.   It’s almost as if the Saskatchewan boundary is a wall, preventing the warmer air from getting in.   Expect another very cold Manitoba day, with highs across the province in the -15 to -20 range.  Snow is not expected anywhere in Manitoba, with no impediments to travel on major highways.

Wednesday

Alberta

It’s a breezy day across Alberta, with the strongest wind and highest temperatures happening early in the day.   Highs could climb to the mid single digits across the province, with a strong wind, dying down around sunset.   And, because of the drying effect of the downslope chinook wind, no snow is expected, with one possible exception being some afternoon snow at the northern boundary of Jasper national park.   That snow, if it happens will come in on a warm front originating from a Low at Haida Gwaii.

Saskatchewan

Snow returns to Saskatchewan, but only in the far northern reaches.   Central and southern Saskatchewan will remain dry, as the flow of mild, dry Pacific air continues.   Temperatures will climb above the melting point south of Saskatoon and across north central Saskatchewan.   There will be a strong westerly wind, though, and that will make it feel colder than the anticipated highs between 0 and 5.

Manitoba

Finally…a breakthrough for southern Manitoba, as it gets to share in the warmth enjoyed by its western neighbors all week.   A strong wind will usher in mild Pacific air, and temperatures through the interlake and in southern Manitoba west of the Red River should climb slightly above the melting point.   East of the Red River Valley and the lakes, it will warm to between 0 and -5, and there will be snow.  It will also snow significantly in northern Manitoba, with moisture coming in off a Low in Hudson Bay north of Churchill.

 

The Polar Vortex!!!

It’s about to get a whole lot colder on the prairies, especially in Saskatchewan and Manitoba, but Alberta won’t be entirely left out.    And, this time, it can be properly blamed on, or credited to, the Polar Vortex.    It has taken an elongated shape, allowing for something called a cross-polar flow.    As the map below shows,  cold Siberian air is flowing across the north pole, directly into North America, especially the eastern Canadian prairie and the midwestern US:

Courtesy: Earth Nullschool

The map is showing the flow way up at the top of the atmosphere.  All this bitterly cold air could produce wind chills in the -40s from eastern Alberta across to southern Manitoba by Monday morning.  Fortunately, this is a dynamic pattern, and the cold outbreak we’ll experience this weekend won’t last long.  Unfortunately, it’s not going to bring much in the way of beneficial precipitation.

 

Thursday

Alberta

The Haida Gwaii Low that’s expected to push snow into the Jasper area Wednesday will quickly cross northern BC, and redevelop Thursday in east central Alberta.   It will bring a swath of significant snow (15 to 25 cm) in a line from High Level southeast to Saskatoon, Saskatchewan.  A front produced some snow Thursday morning through central Alberta.   That has now dissipated, but strong wind can be expected to continue.    Southern Alberta (where snow is badly needed) will stay dry, but the wind in southeastern Alberta will pick up late in the day and into the evening.   The evening wind could cause blowing snow in those areas where loose snow is on the ground.   Further south, it will be dry, windy and warm, with double digit highs possible along the foothills.  Elsewhere in the south and south-central regions, highs should reach 0 to 5 degrees.   Because of the changing weather pattern, this is the last day of the warm spell.

Saskatchewan

A low tracking across Alberta early in the day, plunks itself over central Saskatchewan in  the afternoon.   North of the low, expect a relatively narrow band of snow from Meadow Lake southeast, all across the province to Yorkton.   The heaviest snow within that swath can be expected north of  Saskatoon toward Prince Albert.  South of the Low, in southern Saskatchewan, a westerly wind will continue to produce dry weather, with highs again climbing above zero, especially in southwestern Saskatchewan.   East of Moose Jaw, highs will likely peak between 0 and -5.

Manitoba

A Low in Saskatchewan will stretch a weak warm front into southern Manitoba, so light snow can be expected in the southwestern part of the province by early afternoon, expanding to the rest of southern Manitoba  by evening.     We’ll get another warm day out of this, with highs in southern Manitoba ranging from 0 to -5, -5 to -10 in central Manitoba, and up north, highs of -10 are possible.

 

The animated map below shows the invasion of Arctic air expected from Friday through Sunday.    The first frame in the animation shows temperatures expected midday Friday.   The last frame shows temperatures expected Sunday in the late afternoon.   Note the very cold conditions expected in eastern Alberta and western Saskatchewan this weekend,  with temperatures in the -30s on Sunday:

Courtesy: Pivotal Weather

 

 

 

Friday

Alberta

The weather pattern changes, and it gets colder.  And snowier.  At the surface, an Arctic high develops in the Territories, northwest of Alberta.   The wind in Alberta shifts from the warm west to the cold north, and with that change in the weather pattern, there will be snow across most of southern and central Alberta.   Light snow will fall through most of the day, peppering Alberta’s agricultural lands with some much needed moisture.    As the northerly flow takes over during the day, we can expect a reverse temperature trend for Alberta.   In other words, it will be warmer in the morning than in the afternoon, when temperatures will fall to between -5 and -10.   In Northern Alberta, highs will be closer to -20.

Saskatchewan

The warm spell is over, and most of Saskatchewan will fail to warm any higher than about -15.   Like Alberta, there will be a reverse temperature trend, as it gets colder in the afternoon than in the morning.   Morning temperatures will start out near -15, and by the afternoon, it’s closer to -20. Arctic air returns, and along with it, some snow,  which will fall in central and southern regions through  the day.  It will be light snow, so there will be little accumulation on top of the heavier snow that fell Thursday.

Manitoba

Manitoba’s exposure to warmer air this week was all too brief.  Friday, cold weather returns, with temperatures remaining below -10.  A low passing across the interlake will bring snow to south cnetral Manitoba,, and indications are it will be accompanied by a strong wind.   Travel in the region Friday morning is likely to be disrupted by blowing and drifting snow, and a high wind chill.    The storm system is moving quite fast, and conditions should improve in the afternoon.

 

Saturday

Alberta

Arctic high pressure covers the province by Saturday afternoon, and the light snow expected in southern and central Alberta Saturday morning will be quickly pushed off to the south.   As the Arctic high moves in, the sky will clear, and there will be afternoon sunshine.  Don’t be fooled by the sun.   This is an arctic air mass, and it will be cold, especially east of  highway 2, where temperatures are likely to hover in the low to mid minus 20s during the day.   West of highway 2, temperatures will peak in the minus teens.

Saskatchewan

Mid afternoon temperatures will fall  to the mid minus 20s, as the Arctic high moves in.  Earlier in the day, there will be scattered snow bands in southern Saskatchewan, but as the high moves in, the snow moves out, and at the end of the day, there will be little new snow on the ground.   Cold weather is the big story in Saskatchewan on the weekend….animals ought to be sheltered indoors where possible, and vehicle batteries will need to be kept warm.

Manitoba

Any lingering clouds in southern Manitoba will clear out, as very cold Arctic air circulates into the province around a surface high stretching from southern Alberta all the way to Victoria Island in the arctic archipelago.   All day, temperatures will linger in the -20s, with wind chills in the -30s.   No significant snowfall is expected, or, for that matter, even possible.

 

Sunday

Alberta, Saskatchewan, Manitoba

On Sunday, the arctic high is centered over Medicine Hat, clearing out the sky all across western Canada from Vancouver Island to Ontario.    All three prairie provinces will be dry, and all three will be cold, especially from southeastern Alberta all the way into northwestern Ontario and beyond.   The map below shows afternoon temperatures across the prairies.   Southern Alberta won’t be quite as cold as the rest of the prairies, where, even in the afternoon sun, temperatures will be planted in the -20s.

Courtesy: Pivotal Weather

 

 

COMPARE: Prairie Weather This Week – Midweek update Jan 2

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