Canadian snow gauge experiment: recent results

For several years the Hydrometeorology Division of the Atmospheric Environment Service has been conducting field tests on the accuracy and performance of various types of snow gauge installations used throughout Canada. This paper reviews results on the performance of two types of shielding for recording gauges - the Wyoming shield and a large Nipher-type shield now under test by the AES. The advantages and disadvantages of each type of shield are reviewed. Seasonal totals show that on the average the large Nipher-type shield undercatches the standard MSC Nipher snow gauge by less than 10%, while the Wyoming shieldied gauge undercatches it by about 25%. Alter-shielded recording gauges generally measure about 60% of the snowfall measured using the MSC Nipher shielded snow gauge. Inconsistencies in the daily measurements from some recording gauges were observed and these must be understood before the gauges can be operated successfully at automatic stations in Canada.