Courtney's Cloud Corner: Hail vs Graupel

There are several different types of precipitation that can come from a cloud, but two of them can be hard to distinguish.

As we look into the future of severe weather, different forms of precipitation can form.  Two of which that are difficult to distinguish are hail and graupel. Both look the same and are formed from the same cloud - the cumulonimbus cloud. Within the cumulonimbus cloud, an updraft ascends the water droplet above the freezing level to which the water droplet then freezes and condenses. It then becomes heavy and drops to the form of hail. Hail is usually formed when the cumulonimbus cloud has temperature below and above freezing in order for the water droplet to freeze. Although with graupel, the cloud has to remain mostly below freezing with some areas cooler than fifteen degrees. Graupel is a mixture of supercooled liquid water droplets and snow. Since it has this mixture, it tends to be softer and more brittle.   So a simple way to tell the difference between graupel and hail is to rub the pellets together and see if it’s easy to break or not. If it breaks, then its graupel, if it does not, it is hail.