Hailstorm is a very curious geographical and climatic phenomenon. A hailstorm is named such, due to the fact that during the storm, hail or balls of ice fall in huge quantities on the Earth. It is nothing but irregular lumps or balls of ice. The specialty of a hailstorm is that both hail, i.e. balls of ice, and rainwater fall during the storm, at the same time. In regions that fall outside the tropical belt, hail is accompanied by ice that is so thin that it forms a translucent sheet in the atmosphere. Hailstorms also occur in many tropical and monsoon regions of the world. These, however, are not severe and destructive. At times, these types of smaller hailstorms are joyously welcomed by people residing in the tropical, subtropical, and monsoon regions after a long and dry summer.
Hailstorms, though destructive in nature, are a form of precipitation, like snow and rain, and are thus, unavoidable. The ice ball that falls down from the sky with a great force during this phenomenon is known as a 'hailstone'. An average 'hailstone' can have diameter ranging between 5 to 150 millimeters.
The hailstorms are not exactly storms, but are a side effect of a much bigger storm, the thunderstorm. In fact, this phenomenon originates from thunderclouds.
The hail originates from thunderclouds that are also known as Cumulonimbus clouds. Weather forecast agencies and departments, newspapers, TV channels and other media organizations, do not refer to the actual size of a hailstones in millimeters, while reporting the severity of a hailstorm.
The objects of comparison that are often used are, coins like, cents, dimes, or dollars. Some other objects also include marbles, golf balls, and peas. For Example: Last night's hailstorm, was not very severe and the size of hail was equivalent to that of a 'pea'.
Often, a thunderstorm is followed by this phenomenon. When the existing temperature of a mass of air currents falls down rapidly over decreasing altitude, it results in a hailstorm. The hailstones are formed due to the process of freezing and grow over time. They are carried by the updrafts or the air currents moving in the upward direction, until they become large in size for these currents to continue carrying them. Thus, they are carried downwards by the downdraft air currents.
Hailstorms have rarely lasted for more than 15 minutes. The median of the time span of these storms is about 6 minutes.
According to the meteorological departments of governments all over the world, hailstones must have at least ¾ inch of diameter to become severe, and cause a substantial amount of damage to life and property.
Hailstorms usually occur mostly in mountainous regions than the regions with a lower temperature.
Being a nature's phenomenon and a type of natural disaster, hailstorms are unavoidable, but many of the nations and regions who repeatedly suffer from this phenomenon, have set up an excellent infrastructure for recovery, rescue, and remedy.
One of the most severe and dangerous hailstorms that occurred in the modern times fell on the night of 7th of July, 2009, in a suburb of New York, known as Yonkers. The storm left behind a two inches thick layer of snow, causing a flash flood and also a mudslide.
The largest of all hailstorms was recorded in Aurora, Nebraska, United States in 2003.
Another very big hailstorm occurred early in the 9th century, in Roopkund, India. It is supposed to be one of the earliest officially recorded hailstorms.
In Colorado, United States, the citizens have a 'hailstorm season' that lasts from March to October, every year.