National Weather Service meteorologists measure snowfall by studying radar intensities during winter storms, and more traditional measurements of snowfall rates involve taking ground measurements several times per hour. The more intensely the snow echoes on radar, the faster the rate of snowfall. Lighter radar intensities indicate slower rates. Standard radar images correlate to snowfall rates during a storm based on the intensity and duration of snowfall over a given area.
Snowflakes from very light storms may not show up on NWS radar. When snowstorms produce bigger snowflakes, radar readings indicate how much snow is falling. Meteorologists interpret radar echoes to accurately determine how much snow falls in a certain time period.
NWS weather stations typically take snow depth measurements several times across a six-hour span on snowboards, which are cleared four times per day. Meteorologists report 24-hour and complete storm totals during and after snowstorms.
Amateur meteorologists can measure snowfall several times per hour using a snowboard and ruler to determine the rate of snowfall. For instance, one measurement taken at 5 p.m. indicates a depth of 3.5 inches, and another measurement 15 minutes later shows a depth of 3.6 inches. The change of 0.1 inch is multiplied by four to get 0.4 inch of snow per hour. Automated snowboards with depth sensors have been available since 2004.