Why is there a rain of ice in some other countries?

Question

Why is there a rain of ice in some other countries?

Answer 1

you're talking about hail. one of precepitation forms. Hail is precipitation of balls or pieces of ice with a diameter of 5 mm to 10 cm (about 0.2 to 4 inches). Small hail (also called sleet, or ice pellets) has a diameter of less than 5 mm. Because the formation of hail usually requires cumulonimbus or other convective clouds with strong updrafts, it often accompanies.

In order for the frozen raindrops or graupel to grow into true hailstones, they must accumulate additional ice, a process called accretion. To do so, the hail embryo must spend time in cloud regions rich in supercooled water, a layer where temperatures are below the 0oC (32oF) level.

A layer of drier air in the mid levels of the thunderstorm also assists in hail development. Because very moist air retains more heat, hailstones forming in an extremely moist atmosphere don't freeze properly and resemble soggy slush balls (one reason hail is very rare in hurricanes). As these soft stones fall, they either disintegrate, or simply melt well before reaching the ground.

Storm research has determined that hail is most likely to form when the height of the wet-bulb zero level falls between 2200 and 2800 metres (approximately 7000 to 9000 ft). The wet-bulb zero level is an adjustment to the altitude at which the melting point of ice (0 C) occurs and takes into account the added cooling effect generated by the evaporation of precipitation into the surrounding air. Precipitation falling through relatively dry air can cool the air further by evaporation of liquid water, thus lowering the height of the wet-bulb zerolevel below the altitude of the 0 C temperature isotherm.

Answer 2

In the US, we call it hail storms, same thing.

You can read about it:

http://en.wikipedia.org/wiki/Hail