Monday, February 24, 2014

Frigid finish for February.. coldest winter in Winnipeg in at least 35 years

Simulation of general upper air pattern this winter
showing lobes from the "polar vortex" (outlined)
pushing south into central North America this year
(image credit: earth.nullschool.net)
Another spell of frigid weather is in store for southern MB this week as the relentless winter of 2013-14 refuses to ease its grip across central and eastern North America. Temperatures this week will be running some 15-20C below normal for the end of February, when highs around -6C in Winnipeg are more usual at this time of year. The coldest weather is expected later this week as a surge of bitterly cold Arctic air plunges in from the north, producing daytime temperatures in the minus 20s and nighttime lows in the minus 30s, temperatures more typical of a cold snap in mid January than late February. No way to sugarcoat it folks.. it's just miserably cold and will stay that way all week.  (We're not alone in our winter misery. Check out article on winter misery index to put this year's harsh winter into historical perspective even in the US)
90 day temperature anomalies across the US (deg F)
showing core of abnormally cold temperatures during winter of 2013-14
over central North America
This latest cold snap will ensure that February finishes well below normal in Winnipeg, the third straight month with well below normal temperatures here. February is on pace to finish with an average temperature close to -20C, some 6.5C below normal for February (normal monthly mean of -13.5C in Winnipeg based on 1981-2010 average) This would make this the coldest February in Winnipeg since 1979 which had a mean temperature of -22.0C.  The next coldest most recent February was in 2003 with a mean temperature of -19.4C.

This frigid February will also cap off what will end up as the coldest winter in Winnipeg in at least 35 years. The overall average winter temperature since December 1st will end up around -20C, the coldest winter here since the winter of 1978-79 which had an average temperature of -20.8C.  That winter was the 10th coldest winter on record in Winnipeg going back to 1872.  The coldest winter on record here was 1874-75 with a mean temperature of -23.0C.  (Average winter temperature in Winnipeg is -14.5C, based on 1981-2010 normals.)

90 day temperature anomalies for
Winnipeg Dec 2013-Feb 2014

Mild days have been rare
TOP 15 COLDEST WINTERS IN WINNIPEG  (since 1872*) 

1.      1874-75 ......... -23.0C
2.      1886-87 ......... -22.9C
3.      1883-84 ......... -22.3C
3T.    1884-85 ......... -22.3C
5.      1882-83 ......... -21.7C
6.      1892-93 ......... -21.5C
6T.    1935-36 ......... -21.5C
8.      1887-88 ......... -21.3C
9.      1879-80 ......... -21.0C
10.    1978-79 ......... -20.8C
11.    2013-14 ......... -20.3C   (updated)
12.    1916-17 ......... -20.2C
13.    1889-90 ......... -20.1C
14.    1872-73 ......... -19.8C
14T.  1875-76 ......... -19.8C
14T.  1949-50 ......... -19.8C


"normal" winter average  ........................  -14.5C (based on 1981-2010 normals)

*NOTE: Winnipeg records from Winnipeg airport (1938-current) and St John's College (1872-1938)

Any hope for a turnaround in March? 

Understandably, winter weary Winnipeggers are eager for a change from the below normal weather pattern of the past 3 months. Unfortunately, current forecasts and past history suggest that March will likely remain colder than normal. Of the top 15 coldest winters listed above,  *ALL* were followed by colder than normal Marches (based on a normal temperature of -5.8C for March, 1981-2010 average) The average March temperature following those 15 top cold winters was -12.2C, or over 6C below normal. The warmest March in the group was 1917 at -6.7C, while the coldest was in 1883 at -15.2C.  

It's easy to understand why March would continue below normal following a very cold winter.  A long cold winter will ensure a deep and persistent snowpack well into March, making it difficult for warm air to surface. Solar energy will either be reflected back into space by the snowcover, or be used to help melt the snowpack instead of warming the air. So a lot of energy is lost due to snowcover. Only when snowcover is gone can more persistent warmth become established. But getting rid of snowcover will take time.. unless there's a major shift in the overall pattern to bring persistently warm weather and some rainfall to accelerate snowcover loss. Such a shift is possible, but history suggests that it's not likely to happen. As a result, be prepared for another colder than normal month in March. That doesn't mean every day will be below normal..  we'll have some mild days in there as well. But overall, colder than normal weather will likely predominate during the month.  Note that days are getting longer and the sun is getting stronger in March, so at least the cold won't feel as intense as the middle of winter. Still, the sooner we get back to "normal" weather, the better.

23 comments:

  1. WOW. What a great job that you have done , laying out all of the stats, showing how miserable this winter season really has been. Thanks Rob!:)

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  2. Anonymous..

    Thanks for the kind words. Nothing like some cold hard facts to put things into perspective. :)

    By the way, you can see from that list that winters here in the late 1800s were our coldest winters.. particularly the 1880s which had 4 of our top 5 coldest winters. Don't know how they survived here that decade.

    As for this winter, it has the potential to be our 3rd coldest winter here in the past 100 years.. if we equal or just edge past 1916-17's average of -20.2C.

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  3. Looking at things on the optimistic side...

    According to the stats listed in this post, Winnipeg's coldest winter in the past 100 years was 1935-36.

    However, the summer of 1936 also featured relentless heat, including Winnipeg's all time high: 42.2 Celsius.

    Yes, this occurred in the drought years of the 1930s, but still, it's a nice thought right about now :)

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  4. Hi Rob,
    Was collecting some stats and just noticed an error in the Winnipeg data.. not sure if you noticed it or not. Check out December 22, 1994 in the daily reports:

    http://climate.weather.gc.ca/climateData/dailydata_e.html?timeframe=2&Prov=MAN&StationID=3698&dlyRange=1938-01-01|2008-07-24&cmdB1=Go&Year=1994&Month=12&cmdB1=Go#

    Says low of 7.9°C and high of 1.4°C! I suspect the 7.9°C is supposed to be -7.9°C. Just thought I'd let you know so you could update your data because it actually changes the average for that month. The average minimum of -15.3°C becomes -15.8°C and average mean of -10.7°C becomes -10.9°C. Not sure if you noticed that or not...

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  5. JJ.. Good catch. I hadn't noticed that. You're correct, definitely should be a low of -7.9C. I'll see if they can change that in EC's climate archives.

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  6. By the way, for you webcam fans, the CTV live eye webcam is finally back after being down since before Christmas.

    http://ctvnews.cookieless.ca/cky/webcam/600_wpg_live_eye.jpg

    My webcam page has been updated to include the new image.

    Unfortunately though, CBC's Pembina/Bishop Grandon webcam has not been updating for a few days now.

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  7. That cold front is going to pack some serious punch tomorrow. Temperature falling to -25 with 70km/h wind gusts. A good day to stay indoors!

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  8. Minneapolis recorded their 44th "sub zero F" day of the winter today (below -18C) which puts them close to top 10 territory. NWS MSP has posted a graphic of the top 10 winters with the most sub zero days. The list is very similar to the top 10 coldest winters in Winnipeg.. not surprisingly.

    http://www.crh.noaa.gov/nowcast.php?site=mpx

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  9. Chicago is at 22 days below zero F for the season, and with a few more that will put them in the top 3. Meanwhile we would be begging for a winter with only that many days.

    How many days is Winnipeg at right now??? 70??

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  10. >> Anonymous said...Chicago is at 22 days below zero F for the season, and with a few more that will put them in the top 3. Meanwhile we would be begging for a winter with only that many days. How many days is Winnipeg at right now??? 70??

    Good question. I checked the numbers, and here are Winnipeg stats as of today (from November 1st thru Feb 25th)

    Days below -18C (0F) ..... 82
    Days below -20C .......... 77
    Days below -25C .......... 53
    Days below -30C .......... 24

    When it comes to cold, we're in a different league than Chicago :)

    Look at that -30C stat.. 24 days this winter below -30C, and a few more on the way later this week. Compare that to NONE over the entire winter of 2011-12. Unbelievable.

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  11. These forecasted temps all this upcoming week are just ridiculous. When temps finally get back to normal ( hopefully soon ) we have to start getting some of this snowpack down...which is going to take a long time I feel !!!!

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  12. How many days for the record of winter roads over the ice on lake Winnipeg.

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  13. I'm in La Salle and this the worst winter in 21 years for blowing snow and cold, I think I have more miles on my snowblower than my snowmobile!

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  14. Winnipeg's airport temperature is dropping like a rock. -27 C already.

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  15. Anonymous.. Yeah, it's been a brutal winter. And this latest cold snap is getting past the point of ridiculous. I could accept a cold snap like this if we had a mild winter, but after the winter we've been through.. this type of cold this late is just too much. How much more can we take? Just awful.

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  16. And.. officially -30.0C at the airport as of 11 pm. Our 25th -30C day of the winter.

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  17. Hey Rob, what's the most amount of days below -30 Winnipeg has ever gotten in one winter?

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  18. >> Anonymous said... Hey Rob, what's the most amount of days below -30 Winnipeg has ever gotten in one winter?

    I'll have to check on that. Average is about 13 per year. Today was our 26th day of -30C or lower.. and we'll likely add 3 or 4 more to that total over the next few days.

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  19. I got some numbers re: -30C days in Winnipeg. This is # of days of -30.0C or lower over an entire winter (Nov thru March).

    Most -30C days in a winter..

    1 .. 58 ... 1886-87
    2 .. 57 ... 1874-75
    3 .. 56 ... 1883-84
    4 .. 54 ... 1884-85
    5 .. 46 ... 1882-83

    We currently have 26 this winter as of today and counting. Average is around 13/year (1981-2010 average). As you can see from that list, the top 5 were all from the late 1800s, when they would be calling our current winter "a nice break". :)

    For more recent comparisons,

    1995-96 .... 32 days
    1965-66 .... 29 days
    1978-79 .... 27 days

    So looks like this winter will have the most -30C days since 1995-96. Hopefully we don't beat that mark!

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  20. Some snow moving in overnight through Friday morning.. could see 2 or 3 cm of fluffy snow here in Winnipeg which will make the morning commute a little slick. Northerly winds pick up in the afternoon with blowing and drifting snow for the afternoon commute. What a lovely end to the work week! Stay warm! (..as if I needed to tell you..)

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  21. -46C in Fort Severn, Ontario. Wind chill of -57C. Ouch!!!

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  22. hi rob you do us all a great service especially the snow contractors. I am just wondering where I can go online to see how much snow has actually fallen thanks chris in crestview

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  23. Chris..

    Thanks for your kind comments. You can access daily snowfall data that I take for Winnipeg at the following site..

    http://climate.weather.gc.ca/climateData/dailydata_e.html?timeframe=2&Prov=&StationID=43185

    Daily and monthly data is available from that site. I'm an official volunteer snowfall observer for Env Canada, and my snowfall stats are considered official for the city of Winnipeg, since the airport no longer takes snowfall observations. Note however that I'm in Charleswood and my snowfall reports may not be representative of other parts of the city.

    There are also volunteer snowfall (and rainfall) obs from the COCORAHS observing network, which is an independent private network of volunteers. There's a few observers in Winnipeg who post their data online. You can access the data at..

    http://data.cocorahs.org/cocorahs/maps/?country=CAN

    Hope that helps!

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