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When it hails, ever wanted to run out and catch it? |
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You might not be so keen if the hail was this big! No exaggeration - hailstones can get this large. But what makes them so big? |
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Well, it's important to understand why hail falls in the first place. Clouds are full of water vapour which gathers into tiny droplets around pieces of dust in the atmosphere. |
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They then form bigger droplets until they fall, as rain! |
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But sometimes, conditions change. There are winds, or updrafts, which travel upwards in the clouds, and are able to stop the raindrops from moving downwards. |
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The updrafts also move the raindrops upwards in their clouds. Demonstration time - assuming this piece of sponge is a piece of dust, it gets a layer of water... |
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...then moves up to the top of the cloud. The higher it goes, the colder it becomes. This is where the raindrop freezes. |
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It then becomes a baby hailstone, and it falls back down within the cloud. |
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Here it warms up and picks up another layer of water. It zooms up again... |
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...and freezes once more. The more often this happens, the bigger the hailstone becomes! |
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Eventually it becomes so large, the updrafts can no longer support it, and it falls out of the sky to the ground. |
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Because of all the freezing and thawing, hailstones are layered, just like gobstoppers. Check out the layers inside this one! |
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The world record for the biggest hailstone is 1kg in weight. It was recorded as falling in Bangladesh in 1986! |
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So the next time you're tempted to run out and play in a hailstorm, you might want a hard hat! |
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