On Tuesday, thunderstorms brought small pebbles of ice down to the ground, but what were those icy pebbles called and how did form?
There was a bit of confusion about what it was that fell from the sky on Tuesday. Was it sleet or hail?
It was definitely not sleet. Sleet forms when you have warm air above and below freezing air below. Rain falls through the warm air and then freezes into ice pellets as it moved through the cold air.
Hail is formed in a completely different way.
With hail you have warm air below and sub-freezing air above. As rain falls through the warm air, updrafts within a storm, or winds that blow upwards, push the rain into the below-freezing air higher up. This process causes the rain to freeze.
More and more updrafts continue to coat the hail with more water that turns to ice until the hailstone gets too heavy and falls to the ground. The stronger the updrafts, the bigger the hail stone can grow to become.
This is what happened Tuesday. Strong lifting motion pushed rain into sub-freezing air above and small hail fell down to the ground as a result.
This was not sleet, but sleet is something that we will likely see as we head into the winter months.