A big snowfall can hold a lot of moisture, or very little. Pick the depth and the kind of snow to see how much water it really adds for fields, lawns and gardens.
The old rule says 10 cm of snow melts to about 10 mm of water. Real snow varies a lot. Wet spring snow near freezing packs tightly and can be 5:1 or heavier. Cold, dry snow with fluffy flakes can be 15:1, 20:1 or even fluffier.
Wind matters too. Prairie wind breaks flakes up and packs drifts, so a drift can hold far more water than the same depth of fresh snow.
Moisture from snowmelt is especially valuable in southern Alberta, where summers are dry. A late-season wet snow can do more for a garden or a crop than several dry snowfalls.
Frozen ground, and chinook winds that turn snow straight into vapour, can mean less of that water soaks in than the numbers suggest.