UTAH (ABC4) – Graupel is the soft wintry precipitation that falls during the spring and autumn here in Utah. We have seen it before covering our lawns and when heavy enough covering our roadways causing major delays.
But what exactly is it?
“So, what graupel is it’s supercooled water that builds up on a snowflake,” explains Christine Kruse, Lead Meteorologist with the National Weather Service in Salt Lake City.
The supercooled water encases the snowflake in a thin layer of ice which gives it that opaque look. Graupel while frozen is very delicate and breaks down quickly when touched or exposed to warm surfaces.
Graupel has been called other names as well, such as snow pellets, soft hail, corn snow, and hominy snow.
As it is normally associated with thunderstorms, how common is graupel in Utah?
“So, graupel is very normal in Utah in spring. Anytime we have thunderstorms, we get that cold air coming in we get convection, we can get graupel. We’ve had it cover roads and make it almost like it’s winter,” says Kruse.
As was the case on March 5th, when the one particularly strong storm rolled over the Salt Lake Valley and dropped a decent layer of it on the I-215 interchange causing traffic to back up for quite some time.
While this type of frozen precipitation type has been seen in Utah before, some may not have known the proper name for it and we promise it is not new.
“Graupel is a term we use in the meteorological community. It’s not new. It’s been a persistent term we’ve used for many years and it’s a way to differentiate the different meteorological processes of graupel versus hail,” claims Kruse.
According to the Merriam-Webster dictionary, The term has been used since the late 1800s in weather reports across the meteorology field. The term graupel has a Germanic origin, meaning “pearl barley”.