Chances Of A White Christmas?

courtesy of Environment Canada

 

Environment Canada has provided an analysis of 59 years of weather data (back to the year I was born :-) ) for 43 communities across Canada, which highlights the likelihood of having two or more cm of snow on the ground.   It’s interesting to note that almost all of the cities are now a bit less likely to have a White Christmas than when I was a child.  Only the extreme west and east (Victoria, Vancouver and St. Johns) are now statistically a bit more likely to have a White Christmas (on average).

Since this year (2015) will be the warmest year for the Earth in the past 135 years since records began, it is reasonable to attribute some of this trend to climate change.  In fact, in general, snow amounts have been lower and temperatures have been higher across the country this month… so the chance of a White Christmas in 2015 is actually quite low for many communities.

Screen Shot 2015-11-30 at 9.55.48 PM

 

Besides, climate change, we have an abnormally strong El Nino (warm tropical water temperatures in the Eastern Pacific).  As well, sea surface temperatures are also higher then normal (after a warm summer and autumn) along the Atlantic and Pacific coasts.  This is also contributing to the mild start to the winter. Winter solstice is Monday evening (11:49pm EST) or Tuesday morning (12:49am AST ).

Screen Shot 2015-11-30 at 10.18.03 PM

 

 

For Christmas Eve, the weather pattern is not a typical El Nino pattern.  In fact, western and central parts of the country will be on the cold side. Victoria, who has gone more than 650 days without accumulating any snow (2cm), does have a chance of getting a covering of snow!  However, in Halifax (and in many places in eastern Canada), there is virtually no chance of a White Christmas, as rain and double digit temperatures are likely Christmas Eve.

Screen Shot 2015-12-20 at 8.21.44 AM

The following table charts the amount of snowfall recorded for major cities across Canada from 1955-2013. From this, a probability can be made to determine if a white Christmas will occur for the current year.

­
City %Chance
1955-2013
%Chance
Now

1994-2013
%Chance
Before

1965-1984
Perfect
Christmas

1955-2007
Snowdepth
Now

1994-2013
Snowdepth
Past

1965-1984
Brandon 93 90 95 28 19 12
Calgary 58 55 70 4 5 5
Charlottetown 80 60 95 48 10 15
Edmonton 86 80 100 20 13 17
Fredericton 78 55 85 30 8 22
Goose Bay 98 95 100 53 37 64
Grand Prairie 85 80 100 26 18 23
Halifax 58 45 65 24 3 9
Hamilton 63 60 65 26 6 5
Iqaluit 100 100 100 51 18 20
Kamloops 51 45 55 25 5 11
Kelowna 63 50 75 26 4 8
Kenora 100 100 100 43 23 31
Kitchener-Waterloo 70 60 73 45 6 9
Lethbridge 49 45 55 6 6 5
London 69 55 80 33 7 9
Medicine Hat 56 50 75 17 5 6
Moncton 75 70 80 40 12 21
Montreal 78 70 85 25 9 17
Ottawa 81 75 85 35 19 18
Prince George 92 85 100 40 15 20
Penticton 29 20 35 11 2 4
Quebec 98 95 100 60 25 45
Regina 92 90 95 38 15 14
Saint John 61 45 70 36 4 12
Sarnia 61 40 85 19 4 7
Saskatoon 95 85 100 22 11 12
St. John’s 64 65 50 24 8 9
Sault Ste Marie 81 80 95 69 18 24
Stephenville 83 70 90 64 16 22
Sudbury 95 90 100 46 20 21
Sydney 61 40 65 46 5 9
Thunder Bay 97 90 100 38 13 23
Timmins 98 95 100 46 30 48
Toronto City 46 40 50 9 4 4
Toronto(GTA) 53 40 65 13 4 5
Vancouver 10 15 5 4 4 1
Victoria 10 15 5 6 3 0
Whitehorse 100 100 100 27 18 28
Wiarton 83 75 90 54 16 18
Windsor 46 45 50 4 4 3
Winnipeg 98 95 100 11 14 12
Yellowknife 100 100 100 27 25 24

Definitions

  • % Chance:  probability of a white Christmas (snow on the ground of 2 cm or more on Christmas morning at 7 a.m. EST) for full period of 59 years
  • % Chance Now:  for children today based on period 1994-2013
  • % Chance Before:  for parents today when they were children based on period 1965-1984
  • Perfect Christmas:  snow on the ground of 2 cm or more on Christmas morning and snow in the air sometime Christmas day, i.e., a measurable snowfall on Christmas based on period 1955-2007
  • Snowdepth Now:  average depth of snow on the ground (cm) on Christmas morning from 1994 to 2013
  • Snowdepth Past: average depth of snow on the ground (cm) on Christmas morning from 1965 to 1984

I am sharing some of this with CBC listeners from a number of stations across the country (see below) on the last day of Autumn (Monday 21 December).  At this point, communities in Atlantic Canada have a diminishing chance of a White Christmas, with Western Canadians more likely to enjoy a White Christmas.

My own assessment is:

  • Gander will have a 10% chance or less.  They only have a couple centimetres on the ground, and mild air with rain showers likely overnight Christmas Eve
  • Corner Brook will have about a 30% chance.  Some areas have about 15cm on the ground, but rain and mild temperatures are forecast for Christmas Eve night.
  • Sydney also has only a 30% chance.  Some spots have 30cm on the ground, but rain and 6C Thursday will be followed by 10C Friday.
  • Halifax has less than a 5% chance.  There is only a dusting and mild temperatures and rain are also forecast for Christmas Eve.
  • Thunder Bay has about an 80% chance of keeping the 10cm or less they have.  There may be a bit of snow early Wednesday; but along the lake it may change to rain… making a chance of a Green Christmas along the Lakeshore.
  • Saskatoon has a 95% likelihood of keeping its 10cm or so of snow on the ground, with additional light snow possible Wednesday as temperatures drop during the week.
  • Yellowknife remains cold and has 100% sure thing that the 30cm on the ground will remain.
  • Kamloops has about a 80% chance of a White Christmas as the temperature will remain near or below zero this week, and some brief light snow is expected.
  • Victoria has about a 30% chance of have some wet flurries Thursday night.

While a white Christmas is nice, a green Christmas can be a welcome benefit to travellers.

Stay safe, Merry Christmas and Happy Holidays.

Jim

 

 

 

Frank and Oak, Arbys Closing, Liquormen’s Whisky

A COMICAL CHRISTMAS CAROL W/ RHYS BEVAN JOHN