Turbo Pudding

PitterplopThe real story

Two little clouds make hail look easy. Real hail takes a thunderstorm

· The Turbo Pudding team · 4 min read

On a leafy branch beside the Old Oak’s wide brown trunk at dusk, Gilby, a little honey-colored axolotl with feathery gold gills, a small blue raindrop on his forehead and a green leaf scarf, stands under a glowcap, a mint green mushroom with pale spots on a short white stem, and smiles with a nervous drop of sweat on his head, while a round icy hailstone with a pale rim lands right on top of the cap; Pitter, a pale blue-white cloud puppy with floppy ears and a smug sleepy face, floats at the left by the trunk, Patter, a lilac cloud puppy with a happy open smile, floats at the right, and big blue dewdrops hang in the starry violet sky over soft pink clouds

In Pitterplop, Gilby climbs the Old Oak in Mossy Hollow, and partway up, two little cloud puppies start pelting him with hail. Pitter is sky blue with one curl on top, Patter is lilac with two, and both look very pleased with themselves. Their hail is tidy: a few round stones at a time, each one announced a second before it lands.

Real hail is nothing like that. This Thursday, the real story behind the stones, with facts from the National Severe Storms Laboratory and the National Weather Service. The picture at the top shows the safest spot on the Old Oak. More about it at the end.

Hail on the Old Oak

Old Oak Climb is the fifth level of Mossy Hollow, one tall tree from the roots to the crown. On the upper part of the climb, the twins drift in at the top of the screen. About every three seconds they squash up with a giggly puff and let a volley go: up to three stones, one aimed where Gilby is headed and the rest round about. The aimed stone only comes when Gilby is on his feet, because in midair he couldn’t dodge it.

A wooden sign spells out the rules: “Hail! A frosty ring shows where each stone will land. Keep moving, or wait under a cap or a branch.” The ring grows for exactly one second before the stone arrives. Branches, leaves and open glowcaps all count as shelter, so a stone that meets one cracks on the wood or bounces off the cap before it ever reaches Gilby.

High on the Old Oak at dusk, Gilby, a little honey-colored axolotl with feathery gold gills, a small blue raindrop on his forehead and a green leaf scarf, stands on a leafy branch and looks straight up at a round icy hailstone with a pale rim and a white glint falling right above him, a faint frosty ring on the branch under his feet; a second hailstone falls to his right over another frosty ring, Pitter, a pale blue-white cloud puppy with a smug sleepy face, floats at the left in front of a mossy ledge on the trunk where a grumpy snail sits by a glowcap that a third stone is about to hit, and Patter, a lilac cloud puppy with a happy open smile, floats at the right in a starry violet sky over pink clouds
Searched “how to read a frosty ring.” Look up first.

How real hail forms

Real hail is solid ice, and it forms inside thunderstorms. Strong rising air, the updraft, carries raindrops up into extremely cold parts of the storm, where they freeze. Each little ice ball then grows by running into drops of liquid water that freeze onto it. Water that freezes instantly traps tiny air bubbles and makes cloudy ice. Water that freezes slowly lets the bubbles escape and makes clear ice. So a hailstone can have layers of clear and cloudy ice, depending on the temperature and water it meets on its way through the storm.

The stone falls when the updraft can no longer hold it up, either because the stone got too heavy or because the updraft got weaker. So the twins, two small fluffy clouds, could never make hail on their own. It takes a thunderstorm.

Pea, quarter, softball

To count as hail, a stone must be at least 0.2 inches across. Smaller, softer pellets are graupel, also called soft hail, and they tend to fall apart in your hand. Real hailstones are rarely as round as the ones in the Old Oak. They come in all sorts of shapes, with lumps and bumps and sometimes even small spikes.

People usually describe hail by comparing it with something familiar. A pea is a quarter of an inch, a penny three quarters, a quarter one inch, a golf ball an inch and three quarters, a baseball two and three quarters, and a softball four inches. The quarter matters most. The National Weather Service calls a thunderstorm severe when it can produce hail an inch or larger, or wind gusts over 58 miles per hour.

Under a dark violet sky with pale stars and the dark edge of the oak’s crown at the top right, Gilby, the honey-colored axolotl with feathery gold gills and a green leaf scarf, has just been hit by a hailstone: he hops up off a leafy branch with his eyes squeezed shut and a frown while little white chips of ice fly off his head; Pitter, the pale blue-white cloud puppy with a smug sleepy face, floats at the left under a higher branch where another stone streaks down toward a frosty ring, and Patter, the lilac cloud puppy, smiles at the right; blue dewdrops hang in the air and soft pink clouds fill the background
Typed “does hail hurt?” Gilby would like a word.

Faster than you think

Hail comes down fast. Stones under an inch fall at about 9 to 25 miles per hour, stones of 1 to 1.75 inches at 25 to 40, and stones of 2 to 4 inches at 44 to 72. The biggest, over four inches, can pass 100 miles per hour. In strong wind, hail can even fall at an angle or almost sideways.

Hail falls in paths called hail swaths, anywhere from a few acres to 10 miles wide and 100 miles long. Florida has the most thunderstorms in the country, but Nebraska, Colorado and Wyoming usually have the most hailstorms. Where the three states meet, in “hail alley,” there are seven to nine hail days a year on average.

The stone from Vivian

On 23 July 2010, a powerful thunderstorm crossed central South Dakota. In the small town of Vivian, someone found a hailstone 8 inches across and 18.625 inches around, weighing 1.9375 pounds. The National Weather Service office in Aberdeen measured it, and it became the United States record for diameter and weight. The stone had actually shrunk before anyone could measure it, partly because the power went out at the home of the person who found it.

The weather service put the storm’s updraft at 160 to 180 miles per hour.

Back under the cap

And the picture at the top? That’s Gilby under a glowcap, waiting out a volley while a stone lands right on the cap above him. In Pitterplop, a mushroom is a perfectly good roof. Real hail would call for a much sturdier one.

The first two levels of Pitterplop are free to play in your browser at pitterplop.com. Mossy Hollow, with the Old Oak and the hail twins, comes with the full game, $4.99, paid once. More about the game is on its Pitterplop page.

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