You step outside during a cold shower and little white balls are bouncing off your jacket and the pavement — soft, round, and crumbly, not the hard clear stones of a summer storm. They crush into powder when you pinch them. That's graupel (pronounced GROW-pel, from the German for "pearl barley"), one of the most commonly misidentified forms of winter precipitation. It isn't hail, it isn't sleet, and it isn't quite snow — it's its own thing, and it tells you something specific about the clouds overhead.
Graupel is also called "soft hail" or "snow pellets," and once you know what it is, you'll notice it every cold season. It's harmless, but it's a genuine clue about the physics happening a few thousand feet above your head.
Graupel is born from a process called riming. High in a cold cloud, a normal snowflake begins to fall. On its way down it drifts through a layer of supercooled water — liquid droplets that are colder than freezing, around 23–32°F (−5–0°C), but haven't turned to ice because they have nothing to freeze onto. When one of those droplets touches the passing snowflake, it instantly freezes onto it.
Repeat that thousands of times as the flake falls, and the delicate six-sided crystal gets completely encased in a lumpy shell of frozen droplets. The original snowflake shape disappears, replaced by a soft, opaque white pellet about 2–5 mm across (0.1–0.2 in). Because the frozen droplets trap lots of air between them, graupel is low-density and fragile — that's why it crumbles instead of cracking like hail.
These three get confused constantly because they all fall as small pellets. The differences come down to how they form and how they feel in your hand.
| Type | How it forms | Feel & look |
|---|---|---|
| Graupel (snow pellets) | Snowflake coated in frozen supercooled droplets (riming) | Soft, white, opaque, crumbles when squeezed; 2–5 mm |
| Sleet (ice pellets) | Melted snowflake that refreezes into a solid ice bead falling through a cold layer | Hard, clear/translucent, bounces, doesn't crush; 2–5 mm |
| Hail | Ice grown in violent thunderstorm updrafts, cycling up and down | Hard, layered like an onion, can be huge; usually summer |
The quickest field test: squeeze a pellet. If it crushes into soft crumbs, it's graupel. If it stays hard and bounces, it's sleet. And season matters — graupel and sleet belong to cold weather, while damaging hail is overwhelmingly a warm-season thunderstorm product.
Graupel shows up in cold, unstable, shower-type weather rather than steady all-day snow. Think of the back side of a passing cold front, mountain snow showers, or a wintry day with sun-and-cloud "convective" bursts where quick showers pop up and fade. Those bubbling cumulus-type clouds are exactly the ones that hold pockets of supercooled water for snowflakes to sweep up.
It's especially common in mountainous and high-elevation areas, where skiers and hikers see it constantly. Because graupel is round and low-density, a fresh layer of it acts like tiny ball bearings on slopes — which is why avalanche forecasters pay close attention when a graupel layer gets buried under later snow.
Not exactly — but it does mean the atmosphere is unstable and showery. Graupel forms in the same kind of churning, vertically-growing clouds that can also produce brief heavy snow squalls, gusty winds, and even the occasional flash of thunder ("thundersnow"). So a burst of graupel is a sign the weather is active and changeable, not settled. If you see it alongside dark, towering clouds, expect quick, hit-or-miss showers rather than a calm afternoon.
Graupel is a soft, white, crumbly pellet that forms when a falling snowflake collects a shell of frozen supercooled droplets — a process called riming. It's harmless and fascinating: not hail, not sleet, but a snowflake wearing an icy coat. Squeeze one to identify it, expect it in cold showery weather behind fronts and in the mountains, and remember it can make surfaces slick. Next time little white beads bounce off your sleeve, you'll know exactly what the sky is doing.