This map of snow water equivalent shows the amount of water contained in the snowpack–essentially, the depth of water released if the entire snowpack was melted instantaneously.
The map comes from the National Operational Hydrologic Remote Sensing Center, which also provides information about snow depth and other snow-related variables.
Snow water equivalent provides useful information for water supply (and things like soil moisture for agriculture and other land uses) as well as for flood forecasting. It’s an important number to watch during the spring months, particularly along the Nebraska-Iowa and North Dakota/South Dakota-Minnesota borders.
In these areas, the snow is melting (at last!). But there’s been a lot of snow over much of the upper midwest this winter, and it’s melting quickly. That can mean lots of surface runoff, especially in areas of deep frost, which can cause localized flooding. Eventually, this runoff makes it into the rivers, where high water levels and potential ice jamming can lead to rivers spilling over banks and levees, resulting in property damage, and in some cases, potential loss of life.
The National Weather Service has a flood safety website to help you learn about the flood danger in your particular area and review safety tips. Understanding the danger as well as the actions you can take will help you be better prepared if or when flooding does occur.