Alberta Clipper Brings Back the Deep Freeze

After enjoying a well above-normal –2°C daytime high on Monday, things are set to plunge back into the deep freeze as an Alberta Clipper low pressure system tracks into Ontario and allows a new supply of very cold Arctic air to surge southwards across the Prairies.

The Clipper

Wednesday

-9°C / -26°C
Mostly cloudy; flurries likely. Windy.

A potent Alberta Clipper will move through Manitoba today with the bulk of it’s snow falling along a line from Flin Flon through Norway House and Beren’s River where anywhere from 4–10cm can be expected. Further south, we’ll see light snow through the Parkland and Interlake through much of the day, but the snow won’t start in earnest until the afternoon along and south of the Trans-Canada Highway when the cold front associated with this system moves through.

And what a cold front it is! Yesterday saw genuine flash-freezes in the high plains of the Rockies; Dawson Creek, BC had it’s temperature fall from +5°C to –16°C in just 3 hours. In Grand Prairie, AB temperatures plummeted similarly, with temperatures falling from +5°C to –15°C in just 3 hours as well. It’s this intense blast of arctic air which will help this system produce snow despite the fact it is lacking considerable moisture.

While temperatures won’t be set to plummet quite so dramatically further east in Manitoba, we’ll certainly see the cold air return with a blast. We’ll be dealing with snow, wind, blowing snow and bitterly cold temperatures/wind chill by the end of the day today. Here’s what you can expect:

Snow: We’ll likely see scattered light flurries through the morning and early afternoon. Marginally more organized snow will try to push in through the afternoon along the cold front, but the system will have difficulty producing much snowfall anywhere other than along the northern edge of the track of the low pressure system. By the time things taper off this evening, anywhere from just a trace of snow to 2–3cm will likely have fallen in Winnipeg & the Red River Valley.

Wind & Blowing Snow: Winds will remain fairly light through the day until the passage of the cold front early this afternoon. Behind the front the winds will flip to the northwest and pick up strength to 30–40km/h with gusts as high as 60km/h. This wind will couple with the loose snow on the ground and the falling snow to produce widespread blowing snow through much of the Red River Valley. The worst areas for blowing snow will be the western and central RRV on any west-east running roads, including the Trans-Canada Highway between Winnipeg & Portage la Prairie. If you have plans to travel west on the Trans-Canada Highway today, be prepared for slippery roads with snow and blowing snow producing very poor visibilities.

Falling Temperatures/Wind Chill: Temperatures will fall quite aggressively behind the cold front with temperatures dropping from our daytime high of around –9°C to an overnight low of around –26°C. The cold temperatures coupled with the wind will produce wind chill values near –35 through the overnight hours.

The Remainder of the Week

Thursday

-21°C / -28°C
Sunny & cold.

The remainder of the week through the beginning of next week will be marked by the presence of yet another significant Arctic air mass entrenched over the Prairies. We’ll see mainly sunny skies on Thursday with light winds but temperatures will be very cold. Our high will only climb to around –22 or –21°C before plummeting back down to –28 or –29°C for our overnight low on Thursday night.

Friday

-17°C / -25°C
Some afternoon cloud.

Temperatures will climb a little higher on Friday as a very weak disturbance ripples down the northwest flow, spilling a little bit of cloud across Southern Manitoba by the afternoon hours. The temperature will climb up to around –17°C and we’ll see the temperature drop to around –25°C on Friday night.

Things look clear and cold for the weekend. Another shot of Arctic air will push into the Red River Valley bringing another batch of bitterly cold temperatures and overnight lows near –30°C.

A Brief Reprieve From the Deep Freeze

After a record cold morning on Sunday, we’ll see a dramatic warm-up to start the week.

Temperatures Will be Warming Up on Monday

Temperatures Will be Warming Up on Monday

Monday

Monday

Chance of Flurries in the Morning, then Clearing
-5°C / -14°C

Today will be the warmest day of the week with temperatures climbing into the minus single digits. There may be a few flurries in the morning, before skies clear later in the day. It will be a windy day too, as westerly winds help to bring in that warmer air. Winds will be 20-30km/h gusting to 40-50km/h.

Tuesday

Tuesday

Mainly Sunny
-13°C / -15°C

Temperatures will cool down a bit for Tuesday, with highs in the low minus teens. It will not be as windy as Monday though, so conditions will remain fairly pleasant.

Wednesday

Wednesday

Mainly cloudy. Chance of flurries.
-8°C / -24°C

A low pressure system is expected to pass through Manitoba on Wednesday, signalling the beginning of the end of this little warm spell. At this point it appears that this system will pass far enough to our north that we won’t see much, if any, snow with it – although that may change. Temperatures on Wednesday look to be around -10C with fairly light winds. A cold front associated with this low will move through Southern Manitoba on Wednesday afternoon and evening, allowing another arctic airmass to surge into the region.

Long Range

Models suggest we will continue to see arctic air dominate our weather until Christmas. There may be the odd break in the deep freeze here and there, but in general there are no lengthly warm-ups currently in our future.

Southern Manitoba 2013 Thunderstorm Season Statistics

Editor’s Note: The following is a guest post by @jjcwpg, originally posted here and has been updated with some relevant links from A Weather Moment.


July 13, 2013 southwestern Manitoba; most significant storm event of season; @lovestormsmb and I were there.
July 13, 2013 southwestern Manitoba; most significant storm event of season; @lovestormsmb and I were there.

For the 4th consecutive year, I have gathered statistics on thunderstorm and severe thunderstorm frequency across southern Manitoba. An explanation of how I gathered these statistics as well as notes on accuracy can be viewed here. I have divided southern Manitoba into 6 regions: west, southwest, south, southeast, east and Interlake. These regions can be seen here. I understand the zones are not equal in size; I plan to try to improve this next year. Lastly, I’d like to thank you in advance for taking the time to read this post as it is one of my favourite posts of the year!

Number of days in 2013 thunderstorms were observed in each region.
Number of days in 2013 thunderstorms were observed in each region.

The 2013 thunderstorm season was less active than in 2012 in all regions of southern Manitoba. The greatest decline in thunderstorm days was in the Interlake, southeast and east parts of Manitoba where in some cases there were more than 10 thunderstorm days less than in 2012. The Interlake saw the greatest decline, dropping from 67 thunderstorm days in 2012 to only 55 this year. In total, there were 89 thunderstorm days across southern Manitoba this year, compared with 109 last year.

One reason for the decline is because 2012 had a very long thunderstorm season, lasting from March to November. This year, the first thunderstorm did not occur until April 30, and the last on October 11 putting the season at 165 days long, compared with 237 days last year.

The season began quite late in some areas this year, in large part thanks to an incredibly late spring. The South, Interlake and East zones did not see their first thunderstorm until May 14, 2 months later than last year. On a more local scale, Winnipeg saw its first t-storm on June 10, the second latest start to the thunderstorm season since 1953.

Number of days in 2013 a severe thunderstorm warning was issued for each region.
Number of days in 2013 a severe thunderstorm warning was issued for each region.

Again in Winnipeg, there were only 17 thunderstorm days this year at the airport, tying for 4th least in a year since 1953. It just so happens that one of the years we tied with was 2011. This really follows the trend of the past few years of below normal thunderstorm activity in the city. The last time we had an above normal season was 2007. The last 6 years have averaged some 6 days below the 1981–2010 and 1971–2000 normal of 26 to 27 days.

In comparison, Brandon had 23 thunderstorm days this year, and I recorded 20 here in south St Vital.

The map to the left shows the number of days with a severe thunderstorm warning issued by Environment Canada in each warning zone. It appears southwestern Manitoba was the busiest this year for severe thunderstorms. The season in Manitoba lasted from June 9 to September 26, or 110 days, compared with 116 days last year. Click here for a map of the length of the severe thunderstorm season in each warning zone this year.

Number of days a tornado warning was issued in each region through 2013. Also plotted are confirmed and unconfirmed tornado events.
Number of days a tornado warning was issued in each region through 2013. Also plotted are confirmed and unconfirmed tornado events.

The last map I have is of tornadoes, as seen to the right. The colours in the warning boxes represent the number of tornado warning days this year, and the dots represent unconfirmed (possible or probable) and confirmed tornadoes (coloured by intensity). Only 4 tornadoes were confirmed, but many more may have touched down.

The most notable twister was in Sioux Valley, First Nation, west of Brandon on July 18. It was a strong EF–0 tornado, and moved right through town, destroying a few homes and leaving a few injured. Other than that, the most significant potential tornado event was in the Pipestone to Hartney area on July 13. Significant damage occurred in the area, including to the arena in Pipestone which half of it had been flattened. It is still up in the air wether a tornado occurred or not. Either way, according to Discover Westman, some recall the storm as being the worst storm in recent memory in southwestern Manitoba.

The storm also only worsened the flooding conditions in Reston, which saw yet another round of biblical rains with the storms. In fact, the town had received about 352 mm of rainfall in just a 24 day period from June 20 to July 13 according to Manitoba Agriculture.

In addition to the rains and winds, 9 cm diameter hail was measured in southeastern Saskatchewan with the storms.

Lastly, the following graph summarizes the number of thunderstorm days, severe t-storm warning days and tornado warning days across all of southern Manitoba per month:

Summary of all thunderstorm statistics for all of Southern Manitoba broken out by month.
Summary of all thunderstorm statistics for all of Southern Manitoba broken out by month.

Thanks for reading! A summary of the severe storm season across Canada will come late next week.

Cold Continues Through Weekend

The cold weather plaguing southern Manitoba will continue through the weekend as yet more bitterly cold Arctic air spills southwards. There’s some hope on the horizon that we’ll see temperatures skyrocketing above normal, albeit briefly, so read on to find out what to expect!

Friday

Friday

-24°C / -26°C
Mixed skies and cold with a chance of flurries.

Today will be a very cold day here in Winnipeg; a building Arctic ridge on the north side of a moderately strong baroclinic zone[1] will keep Winnipeg on the cold side of things and bring us one of our coldest days so far: our daytime high will only climb to around –24°C under mixed skies. There may be a slight chance of a flurry, but overall things look to be setting up even a bit further southwest than it appeared on Wednesday and the accumulating snow looks to have shifted out of the Red River Valley. This is not entirely unexpected; when strong Arctic air masses are in place, the models often give the warmer air far too much credit and push things further north than they ought to be. Unfortunately, they don’t always do that so it’s a little touch and go on figuring out whether or not the precipitation tracks are right in the long range.

Skies will become cloudy overnight as the temperature drops to around –26°C and we’ll see a chance of flurries through the night.

Saturday

Saturday

-24°C / -29°C
Cloudy; flurries likely. Clearing overnight.

Saturday will bring cold weather, cloudy skies and a continued chance of flurries. The temperature will once again only climb to around –24°C as we continue to be under the influence of this cold Arctic air. Flurries will persist through almost the entirety of Southern Manitoba as an upper trough slides across the region. We’ll drop to around –28 or –29°C on Saturday night under clearing skies.

Sunday

Sunday

-20°C / ↗ -5°C
Increasing cloud then light snow. Significant warming overnight.

Sunday will be comparable to the last week or so; skies will be mainly sunny until we see some increased cloudiness in the afternoon as some light snow moves into the region associated with a warm front pushing eastwards across the Prairies. We’ll climb to a high of around –20°C. There will be a slight chance of flurries on Sunday night, but we’ll likely just see a stiff wind out of the south as the temperature climbs climbs climbs up into the minus single-digits!

Next Week

At this point, the first half of next week looks quite warm, with daytime highs climbing towards –2 or –3°C. Little precipitation is expected. Unfortunately, and I hate to be the bearer of bad news, but it looks like another brutal cold snap will move in for the end of the week, and at this point it looks like it will be (possible significantly) colder than we’ve seen the past week.

So to make it short: get out there and enjoy the weather through the first half of next week!


  1. A baroclinic zone is an area of heightened temperature contrast; similar to a warm front or cold front but without the significant movement that those features have.  ↩