Presentation description

Many precipitation forecasts are related to the fall speed of hydrometeors, which is related to both mass and density of individual snowflakes. However, a dataset by Locatelli and Hobbs (1974) that is frequently cited, as well as the one that is used in computer models, only contained 376 snowflakes captured in the Cascade mountain range. To improve forecasts, a better understanding of the relationship between hydrometeor mass, density, and fall speed is needed. Prior to this decade, measurements of mass and density for individual snowflakes was not possible, and often required estimations. However, there is now a new instrument called the Differential Emissivity Imaging Disdrometer (DEID) which is capable of this previously impossible task. This device has been deployed alongside a Multi-Angle Snowflake Camera (MASC) to relate mass and density data to snowflake habits, as well as for measurement correction on the DEID. Goals for this study were to examine relationships between various snowflake parameters and relate these relationships to previous research on this topic, as well as comparing specific parameters between the MASC and the DEID. The observed relationships in snowflake mass, density, and diameter, as well as relationships to environmental factors like air temperature and relative humidity, are consistent with previous research.