What synchronizes the growth of the arms? Nothing. The six arms of a snow crystal all grow independently, as described in the previous section. But since they grow under the same randomly changing conditions, all six end up with similar shapes.

ice prisms

ice crystals

List Five Kinds of Snow Crystals

• Simple Prisms. A simple prism is a hexagonal (six-sided) snow crystal.
• Stellar Plates. Stellar plates are flat snow crystals that have six arms stretching out from a hexagonal center.
• Needles. Needles are an interesting type of snow crystal.
• Stellared Dendrites.
• Fernlike Stellar Dendrites.

Water molecules in the solid state, such as in ice and snow, form weak bonds (called hydrogen bonds) to one another. These ordered arrangements result in the basic symmetrical, hexagonal shape of the snowflake. As a result, the water molecules arrange themselves in predetermined spaces and in a specific arrangement.

A snowflake is a single ice crystal that has achieved a sufficient size, and may have amalgamated with others, then falls through the Earth’s atmosphere as snow. Snow appears white in color despite being made of clear ice.

A snow crystal, as the name implies, is a single crystal of ice. A snowflake is a more general term; it can mean an individual snow crystal, or a few snow crystals stuck together, or large agglomerations of snow crystals that form “puff-balls” that float down from the clouds.

When water vapor in the atmosphere condenses directly into ice, bypassing the liquid phase, the resulting forms are properly called snow crystals.

LE Water molecules attach to each other in six-sided rings, like six kids holding hands. When many of these hexagonal rings are joined together, a larger hexagonal crystal is formed. Snow crystals are rarely perfect. So much can happen during a snow crystal’s fall to earth, it is rare that one will turn out perfectly.

Photo by Kimberly Smith. The shapes of snowflakes are influenced by the temperature and humidity of the atmosphere. Depending on the temperature and humidity of the air where the snowflakes form, the resulting ice crystals will grow into a myriad of different shapes.

Snowflakes which collect supercooled water as they fall can fall at up to 9 mph, but snowflakes, as most people recognise them, will tend to float down at around 1.5 mph taking about an hour to reach the ground.

1 to 6 feet per second

32 degrees Fahrenheit

Moisture in the air plays a role, as does the temperature. The temperature of the ground would have been warm enough to melt the snow before it could settle.” The snow that blanketed the south-west was similar to the falls in London, McCallum said, but came at 4am.