Have you ever gone outside after a big snowstorm hoping to make some well-shaped snowballs to throw at your siblings, kids, or friends only to pick up a pack of snow and have it fall apart in your hands? The snow just cannot seem to stick together properly, which you may think is odd because you remember that you have been able to make snowballs before. So, what makes this time different?

The answer lies in the fact that not all snow falls the same way, and no, we are not referring to how every snowflake is unique or anything like that. Rather, we are talking about how snow can have different densities based on the environmental conditions in the atmosphere, whether it be the wet, heavy snow that is always a pain to shovel, or the drier, fluffy snow which may not be good for snowballs but sure is easier to shovel. There are scientific reasons as to why snow may be “wet” versus “dry”, and it has to do with something called the “snow-to-liquid" ratio.

This ratio is defined as the amount of snow that will fall given the amount of rain that would fall if the temperature were warm enough for rain. For example, an old rule of thumb is that 10 inches of snow would fall for every inch of rain that would otherwise fall, i.e. a 10-to-1 ratio. That said, this rule of thumb is far from the norm for every part of the country, as that ratio can vary from region to region and can change based on the environmental conditions at the time of snowfall.

In general, the lower the ratio, the wetter and heavier the snow will be when it falls. A higher ratio typically correlates with drier, fluffier snow.

One of the factors that can play into the snow-to-liquid ratio is the depth of the layer of air from the surface into the cloud producing the snow. The warmer it is (closer to freezing), the thicker this layer is and the lower the ratio will be.

Another factor is the amount of ice in the snow producing cloud. If there are more super cooled water droplets in the cloud, which happens if the temperature is close to freezing, snow ratios will be lower. If there is a higher amount of ice crystals, where the temperature in the cloud is far below freezing, snow ratios will be higher. Deep cold in general, such as that which comes with arctic air masses that intrude the Lower 48 sometimes during the winter, will often coincide with higher snow-to-liquid ratios.

Even the wind can play a factor. In a very windy environment, snowflakes can fracture, losing their "lacy" structure and leading to lower accumulations (lower snow-to-liquid ratios).

So, the next time you’re hoping to make some good snowballs, look for temperatures near freezing to make that ideal wet, sticky snow. If you’re hoping for dry, fluffy snow, look out for brutally cold temperatures to allow for those higher ratios to take place.

-----
Source: NOAA NWS

Featured image via Pixabay.com

Wet Snow vs. Dry Snow: What's The Difference?