The Challenge of Snow Measurements

Abstract

At times beautiful, at times annoying, the importance of snow cannot be diminished by fan or foe. Much has and continues to be written about this crystalline feature, particularly related to disruptive storms, its hydrologic significance and role in influencing and identifying climate variability and change. Many think that measuring snow is simple – nothing more than inserting a ruler and recording the depth. However, whether it is falling, accumulating or changing once on the ground, there are challenges in measuring snow at every stage of its existence. In this chapter we examine historical and current methods of recording the depth and water equivalent of snowfall and snow on the ground. Although the focus is on manual observations, a brief overview of some recent remote sensing methods is also included. Accurate manual snow observations require careful attention to guidelines and exercising careful judgment as one measures this ever-changing medium. Some observers have kept excellent records for extended periods of time and these valuable records are archived at various centers around the world. However, in too many instances both in the past and at present, snow observations are at best granted second class attention by those involved with weather observation, the training of observers and data archiving. This chapter will address the suite of challenges that continue to plague the accurate measurement of snowfall.