What is Snow?

              Snow is precipitation in the form of flakes of crystalline water that fall from clouds. Snow is composed of small ice particles, it is a granular material.

                Snow begins in the atmosphere as water condenses into a tiny droplet. As more and more water vapor condenses onto its surface, the droplet grows. Cold air then freezes this water into ice crystal.

                Each ice crysal has unique shape that depends on the surrounding air’s temperature and water vapor content. If it is below freezing and there is a lot water vapor collects on these branches and freezes, making the ice crstal icreasingly heavy. Eventually, the ice crystal falls from the sky, leaving the cloud of precipitation that it helped form. As it falls, the crystal continues to grow by picking up more water vapor.

                As it descendes, the ice crystal can come into contact with warmer air that makes it melt somewhat. This melting acts like a glue, causing crystal to bond together into larger flakes,  forming what many people think of as the “classic” fluffy snowflake. If the crystal melt too much and then refreeze as the get closer to Earth’s surface, the precipitation falls as sleet instead of snow.

                Once on the ground, snow will remain if temperatures are cold enough to keep it from melting. Glaciers that form on mountains, for example, are made up of snow that accumulates on the ground and eventually turns to ice.