It's snow time! Though you never know how much you are going to get, as I write the rain has turn to snow. I am nestled in and waiting to see how much will fall, with visions of outside adventures fill my head. There will be animal tracking, snowshoeing, sledding and much mucking around in the white stuff. And for the curious among us, if the snow sticks around, an opportunity to explore and discover the science of fallen snow. When it is cold enough and frozen precipitation falls from the sky, it can be hail, ice crystals, snow or other chilly amalgamations. Once on the ground, a whole new language emerges to classify and describe its ground-bound or snowpack state.

Vista M. Kelly, whose work and life are largely unknown to Google (and me), provided this apt quote: “Snowflakes are one of nature’s most fragile things, but just look what they can do when they stick together.”

If you had a field guide to snowpack, it would include a variety of types and descriptors, according to the National Snow and Ice Data Center. Logically enough, when it first falls it is called new snow and has the quality of recognizable crystalline form of the flakes. Quickly it becomes old snow when the crystalline form fades. With sun, rain and other factors, the flakes can melt and freeze together and become granular, taking the name of névé snow.

If the snow persists on the ground for a year, another term, firn, comes into play, describing long-surviving or perennial snowpack, which obviously is impossible to find here. Firn snowpack goes even further in its specificity, requiring a density of greater than 550 kg/cubic meter.

The density and consistency of the flakes isn’t the only thing that changes in snow on the ground. Consider the magic of the forms and shapes that can emerge with the forces of wind, water, freeze and melt. Often a crust will from at the top of the snowpack, and melting can occur from the warm ground surface beneath it. In that case, look for the cornice or overhang that results. A field or other open space affected by winds can lead to snow ripples or corrugation, snow rollers or sun cups, which appear as rolled snow and bowl-shaped formations, respectively.

Though not seen in these parts, other unique structures can appear in snowy settings. In Antarctica, megadunes made up of large, three quarter-inch snow crystals can occur. In dry snow-covered areas such as the Andes, penitents are possible. These tall thin pinnacles can be a few inches to a few feet high. Zastrugi, or Sastrugi, are wavelike grooves or furrows caused by wind and erosion. Drifting snow can further cause barchans, or horseshoe-shaped drifts, and snow bridges which can occur as a cornice grows across from the top.

With all of these snowy sensations, it is not difficult to understand the sentiment of Roger Ebert, the well-known film critic: “The very fact of snow is such an amazement.”

And the varieties, impressive.

Don’t despair if you get blown away by all of the particulars of the powder. After all, it’s easy to get buried in the details, if you catch my drift.

Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown, and author of Martha’s Vineyard: A Field Guide to Island Nature and The Nature of Martha’s Vineyard.