Friday, December 25, 2015

Deepest Christmas snowcover in Winnipeg in 15 years

41 cm of snow over the past week has resulted in the deepest snow cover at Christmas in Winnipeg in 15 years.  As of this morning, the airport was showing a snowdepth of 21 cm, the deepest snowpack at Christmas since a 30 cm reading on Dec 25 2000. At my site in Charleswood, I recorded a snow depth of 30 cm this morning.. the deepest snowdepth on Christmas since Dec 25 2000 (31 cm).        
  
Christmas day snow on ground stats (Winnipeg since 1955)

Least snow on ground....... TR (1997) *
Most snow on ground......... 80 cm (1955)
Average snow on ground.... 16 cm 

* NOTE: Official "snow on ground" readings for Winnipeg airport started in the fall of 1955 and continued until 2002. Thereafter, snow on ground measurements at the airport have been taken by an automated sonic snow sensor at the XWG autostation which uses sound waves to estimate snow depth.  This automated method is not as reliable as human read measurements due to sampling errors caused by drifting, which human based measurements can take into account. Since 2004, manual snow depth readings have been taken at the Charleswood 2 climate site (my backyard) as a secondary source of snow depth measurements in Winnipeg. Note however that snow depth readings at this residential site are generally higher than readings at the airport (by about 30%), owing to the fact that the airport site is more exposed and more prone to blowing, drifting and compacting of the snow pack. 

Prior to 1955, there have been at least 3 Christmases noted with no snow on the ground in Winnipeg: 1939, 1913, and 1877 (based on anecdotal and newspaper reports) Coincidentally, the 4 years with green Christmases in Winnipeg were also the top 4 warmest Decembers on record.

Christmas day snowdepth in Winnipeg since 2000

(Rob's Obs readings)  ........ Airport

2015 ......... 30 cm .............. 21 cm
2014 .........  5 cm   .............   1 cm
2013 ......... 21 cm .............. 10 cm
2012 ......... 24 cm .............. 18 cm
2011 .........   2 cm  ..............  1 cm
2010 ......... 23 cm ................ M
2009 ......... 10 cm ................ 4 cm
2008 ......... 24 cm ............... 14 cm
2007 ......... 28 cm ............... 15 cm
2006 ......... 11 cm ...............  7 cm
2005 ......... 14 cm ................ M
2004 ........... 8 cm ................ 4 cm
2003 ........... 4 cm ................ M
2002 .......... 11 cm ............... 12 cm
2001 .......... 12 cm ............... 12 cm
2000 .......... 31 cm ............... 30 cm

Prior to 1955, there have been 3 Christmases documented in Winnipeg with no snow on the ground, although these are not part of the official climate record. They were 1939, 1913 and 1877. Coincidentally these are There was also reference made that in Dec 1834, the first snow of the season in Winnipeg fell on Dec 28th.. so it's possible that Dec 1834 was also a brown Christmas (but then, we don't know what they considered the first significant snow back in 1834)

Scenes from Christmas Day 1939 in Winnipeg

The following photos are from Christmas Day in 1939 in and around Winnipeg. The photos show Winnipeggers taking advantage of a rare snowfree Christmas day that year with activities like lawn bowling at Assiniboine Bowling Club (bottom left) and golf at the St Charles golf course (bottom right). Dec 1939 was the 3rd mildest December on record in Winnipeg, and included the warmest December temperature ever recorded in the city with a high of 11.7C on Dec 6th.

Winnipeggers pose on a rare snowfree golf course on
Christmas Day 1939 

Lawn Bowling in Winnipeg Christmas Day 1939
Golfing on Christmas Day 1939



4 comments:

  1. Wonder if snow blowing off a roof might contribute to the discrepancy with airport readings versus your back yard?
    What does M indicate on the airport snow depth tables?
    Lastly,did the Woodlands refurbish finish because it's looking unreliable again.
    Happy new year.

    ReplyDelete
    Replies
    1. Anonymous..

      Snow readings in residential areas tend to be higher than at airport locations because trees/buildings/etc allow snow to settle easier instead of blow or drift away like more exposed locations (such as airport, open fields, etc) Simply put, there are more windbreaks in built up areas to allow snow to settle. And yes, snow off roofs can contribute to higher readings in residential areas. On the other hand, snowfall readings at airport locations can sometimes be underdone (especially when wind is present) and may not accurately reflect snowfall amounts in built up areas.

      "M" refers to missing.

      Not sure on the status of Woodlands.. but it wouldn't surprise me if there was still some fine-tuning that needed to be done after the big retrofit.

      Delete
  2. Hi Rob,

    Potential snow next week?

    Thanks

    ReplyDelete
    Replies
    1. Next chance for any accumulating snow is Friday Jan 8th.. could see 2-5 cm for Winnipeg/RRV as system tracks through Dakotas. At this point, not looking like a big event, but system will herald arrival of much colder air for next weekend into next week. New post up...

      Delete