Abstract: The present inventions relate generally to methods, apparatus and systems for measuring snow stability and structure which may be used to assess avalanche risk. The disclosed apparatus includes a sensing unit configured to sense a resistance to penetration as the sensing unit is being driven into a layer of snow. The disclosed apparatus may also be configured to take other environmental measurements, including temperature, humidity, grain size, slope aspect and inclination. Methods and apparatus are also disclosed for generating a profile of snow layer hardness according to depth based on the sensed resistance to penetration and identifying areas of concern which may indicate an avalanche risk. Systems and apparatus are also disclosed for sharing the generated profiles among a plurality of users via a central server, and for evaluating an avalanche risk at a geographic location.