New high-resolution radar measurements performed at the Swiss test site “Vallé de la Sionne” have allowed a reclassification of snow avalanches into 7 different flow regimes. Multiple flow regimes are often simultaneously present in different regions of a single avalanche, and avalanches can change the dominant flow regime as they descend the slope as a result of the entrainment of colder snow at higher altitudes and warmer snow at lower altitudes. 4 of these flow regimes are particularly important for the design of infrastructures impacted by avalanches. These include three dense regimes, namely the cold dense regime characteristic of fast moving dry avalanches, the warm plug and warm shear regimes characteristic of slow moving warm/wet avalanches and one dilute/dense regime, the intermittency regime, characteristic of fully developed powder snow avalanches. Each regime has a distinct impact dynamics, which requires a different modeling approach. The new data suggest that the assumptions underlying current avalanche simulation models and pressure calculation procedures may be too simple. The research community now faces the challenge of developing a better understanding of the physical processes that characterize the individual flow regimes, their transitions, their connection to the snow properties and their interaction with infrastructures.