Snow Depth

GRCA flood forecasters need to know how much snow is on the ground to calculate how much water will run off the land during a snow melt.

The GRCA measures the snow depth at 12 locations throughout the watershed twice a month. The snow survey shows the depth of the snow and how dense it is. From that information, GRCA staff can calculate the water content of the snow.

The snow survey also includes information on whether or not the ground is frozen. That helps flood forecasters predict how much water will soak into the ground and how much will run off during the melt.

Snow survey information is currently not available online.

Satellite snow data

The GRCA takes advantage of satellite technology to get a picture of snow depth across the watershed. This information complements the data from the GRCA's manual snow surveys.

The National Oceanic and Atmospheric Administration uses satellite, airborne and ground-based observations across the U.S. and southern parts of Canada to estimate snow depth.

The GRCA publishes that information on maps showing snow depth and the water content, or snow water equivalent (SWE). The maps are updated daily using information reported at 6 a.m. the previous day.

• View a map of NOAA/SNODAS climate information

About SNODAS

SNODAS is the Snow Data Assimilation System managed by the National Snow and Ice Data Center of NOAA in Boulder, Colorado.