Mountain Snowpack

Snow accumulations in the mountains as of April 1, 2007 generally improve moving from south to north and at higher elevations (Table 1). Measured snowpacks are generally below to much below average in the Oldman River basin, average to above average in the Elbow, Kananaskis and Highwood River basins, average to much above average in the Red Deer River basin, and much above average in the upper Bow, Athabasca and Peace River basins. In the Bow River basin north of Banff, near-record snowpack was measured. In the North Saskatchewan River basin the snowpack is above to much above average at higher elevations and below to much below average at lower elevations.

The mountain snowpack is an important source of water supply to reservoirs in the spring. On average, the accumulation of snow at this time of the year is nearing the seasonal total in the Oldman River basin and is normally 80 to 95 % of the seasonal total in mountain areas north of this basin.

Eight snow courses and two automated snow pillow readings were taken at the end of March in the Oldman River basin (Table 2). Generally the snowpack is below average in the higher elevations of the Oldman River basin, with values ranging from 75 to 97% of average for this time of year. At lower elevations (below 5000ft), the snowpack is much below average, ranging from 0 to 67% of average.

Seventeen snow courses were measured at the end of March in the Bow River basin, with values ranging from 93 to 185% of average (Table 3). Snowpack conditions are generally average in the Highwood and Elbow River basins, and above average in the Kananaskis River basin. At nine snow course locations in the upper Bow River basin upstream of Banff, four had snowpack ranking from highest to sixth highest in 30 to 40 years of record, and four locations with a historical of 70 years had snowpack ranking from 5th to 14th highest.

Four snow course measurements were taken at the end of March in the Red Deer River basin, with values ranging from 98 to 137% of average. Three locations had average to above average snowpack for this time of year, while the fourth location had the second highest snowpack in 30 years of record (Table 4).

Three snow courses were measured in the North Saskatchewan River basin at the end of March. Two stations, at 3500 and 4400ft, show the snow water equivalent to be 50 and 82% of average, which is generally below to much below average. The higher elevation station (6300ft) recorded a snow water equivalent value of 132% of average which is above to much above average (Table 4).

In the Athabasca River basin three snow courses were taken at the end of March. Values were 121 and 134% of average at two locations in the mountains, which is generally much above average for this time of year. The snowpack at Hinton is the highest in 33 years of record (Table 4).

Snowpack in the upper Peace River basin in British Columbia is generally much above average, as seen in the B.C. Snowpack and Water Supply Outlook (http://www.env.gov.bc.ca/rfc/river_forecast/bulletin.htm).

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