Snow Can Disappear Before it Melts

There is a lot of concern about flooding this spring with the deep snowpack and the rain this week. Last week Tom Hoverstad at the Southern Research and Outreach Center at Waseca said they did a core and determined that there was just over 3 inches of precipitation in the snow on the landscape. That is a lot of water to run off if it melts quickly along with the rain this week.

However, some snow was disappearing this winter even though it was so cold the snow did not melt. Some of the snow evaporated. Some substances like water can go from a solid state to a vapor state without going through a liquid phase. This process is called sublimation.

Typically when it is really cold in the winter the relative humidity of the air is very low. Some of the snow and ice will actually evaporate. Water will go from a solid state, snow and ice to water vapor in the air without melting first. See for yourself, put an ice cube in the back of the freezer and leave it there for a couple months. When you check it the ice cube will be noticeably smaller. It did not melt, some of the ice evaporated!