Thursday, November 10, 2011

What is Graupel?

Mark it down! Flurries fell at the Cherry Logistics' Weather Center for the first time this snow season.



With a chance of snow flurries present in our forecast today, the radar proves our forecast correct. But one thing that the our meteorologists did not forecast was graupel.


This is a view from the front of our office today. As swath of precipitation came towards us, little white pellets began falling from the sky. Someone asked, "Is it hailing outside?" While graupel may look like hail, they are actually two different types of precipitation. 

Hail is precipitation in the form of lumps of ice. Hail is produced in cumulonimbus clouds. They hail balls grow within the thunderstorm and add a layer of precipitation onto it when moved around in that cloud. Once the hailstone becomes too heavy, the hail then falls to the ground. 
Graupel is made by a riming process as they these snow crystals pass through clouds with supercooled water. When this supercooled water comes in contact with the crystals, they form graupel. Graupel is usually 2-5 mm and is known to fall when it 0° Celsius. 



And just as much as they are called snow pellets, they hurt just like pellets too!



~Meteoroligist Heather Brinkmann

No comments:

Post a Comment