Mountain Snowpack

Snow accumulations in the mountains as of April 1, 2004 are generally below-average to much-below-average in the Waterton/St.Mary, North Saskatchewan and Athabasca River basins, below-average in the Oldman, Bow and Smoky River basins, and below-average to average in the Red Deer River headwaters for this time of the year (Table 1). Little to no snow was measured in the lower elevations of the Waterton/St.Mary and North Saskatchewan River basins. The mountain snowpack is an important source of water supply to reservoirs in the province. On average, the accumulation of snow for 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 were measured at the end of March in the Oldman River basin, with seven values in the mountains ranging from 67 to 95% of average for this time of year (Table 2). The one snow course at lower elevation, Lee Creek, had no snow left as the below-average snowpack there at the start of last month has melted. The snowpack is generally below-average to much-below-average in the Waterton and St.Mary River basins and below-average in the Oldman River basin. Snow accumulation during March was below-average to much-below-average. Current snow accumulations are similar to last year at this time, and much greater than the record low snowpacks of April 2001.

Seventeen snow courses were taken at the end of March in the Bow River basin, with values ranging from 76 to 98% of average (Table 3). Snowpack measurements are generally below-average for this time of year. Snow accumulation during March was average. Snow accumulations are slightly higher than last April, much lower than those recorded in April 2002, and much higher than the near record lows observed on April 1 of 2001.

Four snow courses were measured in the Red Deer River basin on April 1, with values ranging from 82 to 98% of average, which is below-average to average for this time of year. Three snow course measurements were made in the upper North Saskatchewan River basin, with two in the foothills at 0 and 16% of average, which is much-below-average for this time of year, and one in the mountains at 76% of average for this time of year, which is below-average to much-below-average. Three snow course measurements were made in the upper Athabasca River basin, with two in the mountains at 59 and 65% of average, which is much-below-average for this time of year, and one in the foothills at 92% of average, which is average for this time of year. Red Deer, North Saskatchewan and Athabasca snow course data is available in Table 4. Snow accumulation during March was generally below-average to much-below-average in the Athabasca and North Saskatchewan River basins, and near-average in the Red Deer. Mountain snow accumulations in all three basins are much higher than the near record lows observed in April 2001, and generally lower than last April.

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