What is sleet?

GRAUPEL is what happens when snowflakes become covered with ice.

Sleet isn’t hard like hail, but it’s not soft like fluffy snowflakes, in fact it’s similar in composition to Dippin’ Dots ice cream.

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What is sleet?

Sleet is also referred to by many as “soft hail”, but is actually not hail at all.

Instead, sleet is more like tiny globules filled with snow and only lightly coated with ice, making them soft to crush.

To understand how sleet is formed, one must first remember that all winter weather begins as snow high up in the atmosphere.

If the air stays cold all the way down, with no pockets of moisture, then you’ll end up with fluffy flakes.

How is sleet formed?

Sleet occurs when there are clouds in which ice particles, supercooled water droplets, and snow collide when thrown by turbulent air.

Within a cloud that produces sleet, temperatures must be just below freezing (32 degrees Fahrenheit), with some being below 15 degrees Fahrenheit.

This allows both supercooled water droplets and snow to exist in the cloud.

During the process that forms sleet, snowflakes collide with supercooled water droplets thrown through the turbulence.

When these supercooled droplets attach to the snowflake, the droplets freeze instantly on contact, covering the snowflake with a thin layer of ice.

How is sleet different from hail?

Graupel differs from hail both in its production and its composition.

Hail occurs during thunderstorms when raindrops are carried by thunderstorm updrafts into extremely cold areas of the atmosphere and freeze.

The hailstones grow as they collide with liquid water droplets that freeze on the surface of the hailstone.

The hail falls when the storm’s updraft can no longer support the weight of the hailstone, which can happen if the rock gets big enough or the updraft weakens.

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Hail is essentially pure ice and is hard and dense, while sleet is much softer and only lightly glazed with ice.

While hail is unique to thunderstorms, sleet can occur whenever conditions are right.