The difference between "Hail", "Sleet" and "Graupel"?

4/11/2022 (Permalink)

Here in Pottstown PA, we experience all types of precipitation throughout the year. this year was no exception with a mix of graupel, sleet and hail. What is the difference? The National Weather Service defines each as such:

"Graupel" - Heavily-rimed snow particles or snow pellets that can be irregularly-shaped. Riming process acts to "glue" snow crystals together and rain or partial melting adds an icy outer layer.  Graupel is usually less than 5mm in diameter and is typically white, soft, and crumbly and resembles snow more than hail or sleet". 

"Hail" - Hail forms via convective processes that exist in showers and cumuliform clouds.  Hail tends to be opaque/white while sleet is usually more transparent. Generally, if a "ball of ice" is greater than 5mm in diameter, it is considered hail as only convective processes would allow for such growth of the ice. 

"Sleet" - A hard, translucent ball of ice less than 5mm in diameter that bounces when it falls may be called sleet if it is formed the refreezing of liquid raindrops or partial melting of a snowflake.  This can occur via convective processes (when in a shower there is partial melting) or stratiform processes (i.e. overrunning of a stationary front).

**The term "ice pellets" may be used to describe either small hail or sleet, but not graupel. 

Storms like these always have the potential to bring water damages to your home or business.  The team at SERVPRO is ready to face that challenge!