Occasionally, you must have seen, some round balls of ice accompanying heavy rains. These round balls are called hails. They are seen more often in summer than in winter. Hailstones are of varying sizes. You may be curious to know how hails are formed in the atmosphere!
When raindrops start falling from the clouds towards the Earth, sometimes they have to pass through very cold regions and due to this low temperature, these raindrops get frozen. These frozen raindrops are called snow flakes. Sometimes these snow flakes are lifted up by strong winds to regions already having raindrops. As a consequence they get stuck to these snow flakes. When they fall through colder regions of the atmosphere, they are again frozen. This way the size of the frozen raindrops goes on increasing. When the weight of these frozen drops is more than the up thrust of the air, they fall down on the Earth in the form of hailstones.
If you cut a hailstone into slices, you will notice many layers of transparent and semi-transparent snow. These layers are formed by the repeated freezing of the water-drops. The diameter of hailstones varies from 1 cm to 8 cm. A hailstone may weigh even more than half a kilogram. On 6 July, 1928, a very big hailstone fell at a place named Potter, Nebraska. It weighed 717 gm and had a diameter of 15 cm.
Hailstones can cause extensive damage. It has been observed that some animals and human beings have even succumbed to the injuries caused by hailstones. Hailstones are very damaging to the crops – they destroy the standing crops. On 30th April 1886, 246 people died of injuries caused by hailstones in Moradabad in UP (India).
