Frequently Asked Questions
Is snowfall depth the same as water equivalent?
No. Fresh snow has a snow-to-liquid ratio of typically 10:1 to 15:1, meaning 10–15 cm of snow melts to 1 cm (10 mm) of water. Wet, heavy snow may be 5:1, while dry powder can be 30:1 or more.
What is Snow Water Equivalent (SWE)?
SWE is the depth of water that would result from melting the snowpack. A 30 cm snowpack with a density of 300 kg/m³ has an SWE of 90 mm. Knowing SWE is critical for spring runoff forecasting and reservoir management.
How do I convert cm of snow to water?
Multiply snow depth by the snow density ratio. For typical fresh snow (density ~100 kg/m³, ratio 10:1): 20 cm snow → 20 mm SWE. For wet spring snow (density ~350 kg/m³): 20 cm → 70 mm SWE.
What is a blizzard classified as?
The US National Weather Service defines a blizzard as snowfall or blowing snow with winds of at least 35 mph (56 km/h) and visibility of less than 1/4 mile (400 m) for at least 3 hours.
How much does fresh snow weigh?
Fresh snow weighs about 50–100 kg/m³ (0.05–0.10 g/cm³). Settled snow can be 200–300 kg/m³, while glacial ice approaches 830–917 kg/m³.