4.2.10 More about the precipitation types

Click on each type of precipitation to learn more about it.

New freezing rain event.

Freezing rain accumulates as a very dense, hard layer of ice on top of the snowpack.

Graupel falling on the layer of new snow.

Graupel acts as a very dense, heavy layer of particles, which can compact the top of the old snow. When graupel is buried, it is a weakly bonded layer.

Freezing drizzle event after the new snowfall.

Freezing drizzle accumulates as an ultra-thin, very dense, hard layer of ice on top of the snowpack.

Sleet falling on top of the new snow layer.

Sleet accumulates as a dense layer on the top of the snowpack and compacts the top of the old snow layer.

Rain falling on the new snow layer

Raindrops percolate into the top few cm of the snowpack, creating a wet snow layer. The mixture will eventually freeze when temperatures fall. When crusting occurs, the associated heat release caused by the freezing produces a temperature gradient in the snowpack and facets grow on the snow crystals just below the crust, forming flat edges. If snow falls after that point, we'll have a buried layer of faceted crystals next to a hard ice layer, which could lead to cracking and collapsing in the new snow layer.