A rain/snow boundary moves towards the adjacent rain region owing to the progressive cooling of the atmosphere caused by melting snow. The dependence of the width and speed of the boundary on the initial lapse rate, the size of the largest snowflake, the snowflake density, the precipitation rate, and the horizontal temperature gradient is determined using a numerical model. The dependence on relative humidity is explained qualitatively. The results from these calculations predict speeds of about 0.5 m s−1 and widths of about 10 km after 2 days using reasonable values of the governing parameters in a precipitation rate of 1 mm h−1.
ASJC Scopus subject areas
- Water Science and Technology