Mountain Snowpack

Snow accumulations in the mountains as of December 1, 2003 are average to above-average for this time of the year. The mountain snowpack is an important source of water supply to reservoirs in the province. On average, the accumulation of snow at this time of the year accounts for nearly one-fifth of the seasonal total.

There were a limited number of snow course measurements taken at the end of November. More comprehensive measurements of basin snowpack begin at the end of January.

Three snow courses and two automated snow pillow readings were taken at the end of November in the Oldman River basin, with values ranging from 102 to 148% of average for this time of year (Table 1). Snow accumulations are average to above-average and are generally much better than those observed in December 2001 and 2002.

Five snow courses and three automated snow pillow readings were made at the end of November in the Bow River basin, with values ranging from 85 to 129% of average (Table 2). Snow accumulations are average to above-average for this time of year, and are much higher than those observed last year at this time and higher than those recorded in December 2001.

Two snow pillows in the Red Deer River basin show accumulations of 139 to 143% of average on December 1, which is above-average for this time of year (Table 3). Snow accumulations are similar to those observed last year at this time at Limestone and much greater than those measured in December 2002 at Skoki. Snow measurements are similar to those taken in December 2001.

No snow course measurements were made in the upper North Saskatchewan or Athabasca River basins this month.

At twelve snow course sites, real-time snow accumulation can be monitored using snow pillows. Snow pillows can be viewed by choosing any mountainous southern basin, and snow data, in the two drop down menus at:

Snow water equivalent values on the snow pillow may or may not match the snow course value at a particular location. While snow pillow data is very valuable information, the quantity of snow on the pillow is only representative of the accumulation at that specific spot. A snow course survey is measured at numerous spots and provides a more representative value of snow in the area. In some locations, there can be considerable difference between the snow pillow and snow course values. Factors such as wind and exposure of the site can cause the snow pillow values to be significantly different from the snow course survey. The snow pillow graphs on our website show the daily average snow water equivalent. The monthly snow survey is the average of all measurements conducted within five days of the end of the month. Also, where snow pillow and snow course measurements are available for the same site, snow pillow records tend to be much shorter (10-15 years) in length compared to the snow course sites. As a result, the difference in the average value between the snow pillow and the snow course can be attributed to snow water equivalent being derived two different ways (physically measured compared to an instrument reading), site location and length of data record. In some cases, the values can deviate by 10-20%. Therefore, while snow pillows are excellent for analyzing trends and for monitoring accumulation between snow surveys, snow course values should always be used when considering the quantity of snow at a particular location as they best represent that area.

Click here to see a map of snow course locations