Damaging hail sweeps across China

Hailstones are responsible for the destruction of billions of dollars of crops every single year. [EPA]

For two days running, China has been hit by severe thunderstorms.

Heavy rains and strong winds have lashed the southeast of the country, with the greatest damage caused by hail. It seems that the rainy season has started early.

Hunan province was hit on 11 April. Liling County, in the east of the province, witnessed a hailstorm that lasted around 20 minutes. The largest hailstones were over 3cm in diameter and were accompanied by winds of 60kph.

Then just a few hours later, it was the turn of the Fujian province to see the destructive weather.

28 people were injured when hail up to 25mm in diameter pummelled the region. One of those injured had to be hospitalized.

Hail wasn’t the only destructive weather from this system. Lightning also raged overhead and strong winds brought down tiles from roofs. It’s estimated that 1,916 roofs were destroyed by the storm.

Every year hail causes billions of dollars of damage to crops throughout the world. Even relatively small hail can shred plants to ribbons in a matter of minutes. In the US alone, damage from hail approaches one billion dollars each year.

Vehicles and property are also commonly damaged by hail, and on occasions it can even prove fatal to humans. The most deadly hailstorm on record occurred in India on 30 April 1988, killing 246 people and 1600 livestock.

Hail forms in thunderstorm clouds. The forces within these storms are intense, and the water and ice particles are forced up and down throughout the atmosphere.

As the particles rise and more ice solidifies onto them, the hail stones start to grow. Then, as they sink again, they start to melt, before the updraft shoots them skywards once more.

Eventually the updraft within the thunderstorm will no longer be able to support the weight of the ever-growing hailstones, and they fall towards the ground.

Sometimes it’s possible to see layers within a hailstone. When they are cut open, some look like an onion, which shows how many times the hailstone travelled up and down within the storm.

However, the largest hailstones have often begun to melt and have then refrozen together – forming large and very irregularly shaped hail.

The largest ever recorded hailstone fell in Vivian, South Dakota on 23 July 2010. The giant lump of ice measured 20cm (8 inches) in diameter.

These jagged-edged hail stones are to be avoided at all costs.