Sunday, November 11, 2012

Winter storm delivers winter wallop to southern Manitoba

South Winnipeg webcam around
10 pm Nov 10th when heavy snow
was giving 5 cm/hr snowfall rates

Winter arrived with a vengeance Saturday as a well advertised winter storm brought widespread snow across most of southern Manitoba Saturday into Saturday night.  The "Colorado low" storm system which tracked across northern Minnesota last night, brought two waves of snow.. one that began in the early morning hours Saturday and pushed into the Interlake areas, and another heavier burst of snow Saturday night that brought very heavy snowfall rates of up to 5 cm/hr at times across the Red River valley including Winnipeg. When the snowfall finally tapered off Sunday morning, it left some impressive snowfall totals over most of southern Manitoba, transforming what was a bare snowfree landscape Friday into a winter wonderland within 36 hours.

Some storm snowfall totals reported as of Sunday morning Nov 11th..

Mafeking ................. 65 cm   (Highway 10 between Swan River and The Pas)
Ashern ...................... 40-60 cm
Hodgson ................... 40 cm
Swan River ............... 40 cm
St Alphonse .............. 40 cm 
Portage La Prairie ..... 37 cm
Dauphin .................... 33 cm
Baldur ....................... 33 cm
Holland ..................... 32 cm
Belmont .................... 32 cm 
Gilbert Plains ............. 25-35 cm 
Roblin ....................... 24 cm
Winnipeg ................. 22 cm  (greatest 24 hr snowfall since Dec 2006)
St Claude .................  22 cm
Marquette ................. 21 cm
Brandon .................... 20 cm
Neepawa ..................  20 cm
Woodlands ...............  20 cm
Morden ....................  14 cm
Carman ....................  12 cm
Pinawa ...................... 11 cm 
Steinbach  ................. 10 cm
Emerson .................... 10 cm

Backyard scene from Treherne MB
was typical across much of
southern MB Sunday morning
Winnipeg's snowfall of 22 cm was the city's greatest 24 hr snowfall since Dec 30-31 2006 when 32 cm fell. Heaviest snowfall with this storm was in a wide swath from the Riding and Duck Mountains through the northern Interlake, as well as a narrower band from the western RRV through Portage la Prairie into the central interlake thanks to some slow moving heavy snowbands that set up Saturday evening.  Neighbouring eastern Saskatchewan was also hard hit with 30-45 cm reported from Regina to Yorkton. Snowfall was much less south and east of Winnipeg especially towards the Ontario border where precipitation was mixed with freezing rain Saturday.

Trucks line up in Headingley MB
waiting for the TransCanada to open
The storm was bad enough to force the closure of the TransCanada highway Saturday night between Winnipeg and Brandon due to the severe winter conditions.


Storm Chronology for Winnipeg (as observed at my site in Charleswood)

Light snow began around 2-3 am on Nov 10th, with 2 cm falling between 4 and 8 am. Snow continued through the morning with another 3 cm by 1 pm. Snow stopped in the afternoon with some light flurries mixed with freezing drizzle at times. By 5 pm, steadier snow started falling again with another 5 cm by 9 pm. Around 9 pm, snow intensified and became very heavy, with 5 cm falling between 9-10 pm, and another 3 cm from 10-11 pm. Snow started easing around 11 pm with another 1 cm by midnight.  Another round of steady snow developed by 1 am, with an additional 3 cm by 4 am Nov 11th.  Snow tapered off by 6-7 am Nov 11th.  Storm total by 8 am Nov 11th: 22 cm snow, trace of freezing drizzle.

Nov 10 - 11 2012 snowfall accumulations (per my obs and YWG airport obs)

2 am - 4 am:    Trace
4 am - 8 am:    2 cm 
8 am - 1 pm:    3 cm 
1 pm - 5 pm:    Trace of snow, trace of freezing drizzle
5 pm - 9 pm:     5 cm 
9 pm - 10 pm:   5 cm (S+) 
10 pm - 11 pm: 3 cm
11 pm - mid:     1 cm
mid - 4 am:       3 cm 
4 am - 7 am:     Trace  

24 hr Radar accumulation summaries to 9 am Sunday morning

24 hr precip accumulation from
Foxwarren radar to 9 am Sunday.
Precip amounts in mm and
may not accurately reflect
actual snowfall totals
24 hr precip accumulation from
Woodlands radar to 9 am Sunday.
Precip amounts in mm and
may not accurately reflect
actual snowfall totals


  1. Congrats to those who picked 20-25 cm on the snow poll, Winnipeg's storm snowfall. It was the second most popular choice, after 15-20 cm which wins consolation prize. Average guess was 17 cm, which was fairly close overall. Thanks to everyone who voted.. great response!

  2. Great coverage Rob Just in from Crescent Drive park. Still snowng and rough measures 8 to 9 inches OG near RRvr

  3. Some light snow over Winnipeg thanks to a narrow band of lake effect flurries coming in NW flow off Lake Manitoba. This will be enhanced with upper trof swinging through tonight that is supporting area of snow to our northwest. Could see another 2-5 cm tonight as that feature moves through, although some places may see some locally higher amounts under more persistent lake effect band. In contrast to yesterday's snow however, this snow will be the light fluffy stuff.

  4. By the way, yesterday's storm was the greatest 24 hr snowfall in Winnipeg since Dec 30-31 2006 when 32 cm fell.

  5. Thanks for the round-up. What is CYWG using now for the official snow measurements? Just the auto station?

  6. @Garth

    I think I remember Rob saying that his station was the official one for snow measurements.

  7. Re: snowfall measurements at YWG

    Official snowfall measurements haven't been taken at YWG airport since 2008. The automated precipitation gauge at YWG only records melted equivalent of snowfall in mm, but there is no official snowfall measurements (in cm) or snowdepth taken any longer. Melted equivalent of course doesn't tell the whole story of how much actual snow fell, since we all know that snow:water ratios can vary greatly from event to event, and over the course of a winter. Yesterday for example, the airport recorded 15 mm of melted snow. OK, but was that 10 cm snowdepth? 15? 20? 25? We don't know, unless someone took an actual measurement with a ruler.

    And that's where the problem is. The reporting of snowfall at our airports is becoming an issue since NavCanada is taking over responsibility of weather reporting stations at our major airports. Since NavCanada doesn't require maintaining snowfall records, EC has needed to hire contract observers to record snowfall at most of our major airports. The exceptions are Winnipeg, Regina, Saskatoon, and Fredericton where contract observers have not been able to be hired for whatever reasons (which means we still get snowfall data for Victoria and Vancouver BC, but not Winnipeg or Regina.. go figure)

    Because of this issue, I became a volunteer climate observer in 2004 so that there would be SOME record of snowfall in Winnipeg, even though my site is not really a good proxy for the airport (since the airport site is more exposed, they generally would record lower snowfall amounts and snowdepths than at my site which is more sheltered) However, it's better than NO snowfall records at all.

    Hopefully, EC will be able to find a way to get snowfall measurements back at YWG airport some day. And when it comes to snowfall, you really need a human observer to measure it.. automated snowfall sensors are just not reliable or accurate enough. Winnipeg has snowfall records back to 1872.. and it would be a shame to permanently discontinue that lengthy data record. How do you compute 30 year normals of snowfall when you don't keep track of it any more?

  8. Hey Rob, Anymore snow tonight? Is that band of snow to the NW going to hit the Peg?


  9. Thanks Rob. I figured the problem at the airport would only last a winter or two as EC and NavCanada worked things out. I used to get paid only 25 cents/hour extra as an observer to launch radiosondes (great fun, would have done it for free), so surely EC could kick in a few pennies to convince the NavCan FSS staff to head out the door with a ruler once a day.

    I hope it's all being recorded as metadata so climate researchers understand the situation.

  10. Anonymous..

    That band of snow to our northwest is slowly edging towards Winnipeg. Leading edge at 10 pm is from Woodlands to Elm Creek. Should be in Winnipeg by midnight or so.. and last for a few hours, perhaps 2 or 3 cm of fluffy snow before it's through.

  11. Rob, What are the chances of this snow or some of it melting in the next week or so?

    Any large scale warm ups for us on the way as in temps above the freezing mark in next while?

  12. Very interesting snow map...

    You can clearly see where the snow/rain divide was.

  13. 20.3C in Hamilton, Ontario today!!!

  14. In hindsight I'm not sure if anyone got this forecast right in terms of the overall system. Winnipeg was pretty lucky to get that shot of snow Saturday night. Mafeking getting over 2 feet of snow wasn't on anyone's radar!

  15. 1 cm of new snow overnight at my place.. radar shows a band of heavier amounts just west of the city from the southern tip of Lake Manitoba through St Francois Xavier to Beaudry Park.. perhaps another 5 cm in that band. Snowdepth at my site is down to 20 cm.

    Mighty cold to the west of us where skies have cleared.. down to -17C at Brandon with -20C temps near the SK border, and -24C over eastern SK. Our forecast low of -13C tonight under clear skies and diminishing winds with a 20 cm snowpack looks a tad optimistic. Models likely not catching onto the sudden snowpack. I think -18C is possible tonight with a chance of some -20C readings outside the perimeter.

  16. Interesting.. GEM model surface temperatures actually have -20C readings over the Red River valley tonight including Winnipeg, but UMOS warms the lows up to -13C. So it's the statistical processing that is the issue in this case, not the model. UMOS obviously oblivious to the sudden snowpack.

  17. Back at work at NWS GF....great to see the snow your way...a bit farther northwest track worked out per the models the day of and just before the event as it had the warmer air and mixed precip a bit more northwest.

    Grand Forks didnt get much at all...stayed at 32-33 Saturday with drizzle then 1 inch of snow Sat night.

  18. Wow... it's currently 20.5C in Sherbrooke, Quebec and it's only 11AM EST over there.

  19. Hi Dan... It was a tricky storm to forecast, even while it was happening. If it wasn't for that 2hr burst of heavy snow Saturday evening, Winnipeg would have had half the snow amount we got. Jackpot definitely to our north and west in the deeper colder air and more prolonged moisture feed.

  20. Rob,
    Although likely slim, is there any chance we might see some melting of this snow in the next week or so?

    Any possibilities of temps rising above the freezing mark for a few days?

  21. I see E.C. has adjusted it's forecast low for -21C. That's more like it.

  22. Mother of god...

    It's 22.7C right now in Huntingdon, Quebec!!!

  23. CBC News Story: "Storm buries Manitoba town with 65 cm of snow"

  24. Anonymous.. see new post on the expected weather this week into next.