Cloudbursts: Facts, history, world records

As the monsoon swept across India, the country woke out to disastrous news of a cloudburst in the scenic Himalayan town of Leh on Friday, Aug 6.



A cloudburst is defined as an extreme form of rainfall. The downpour is always voluminous and leads to flash floods.

The cloudburst rainfall is sometimes mixed with hail and thunder. It does not last for more than a few minutes but is capable of causing great damage.

The rain from a cloudburst, which descends from very high clouds, has a fall rate equal to or greater than 100 mm (3.94 inches) per hour. Most cloudbursts come from convective, cumulonimbus clouds that form thunderstorms.

The extent of damage that a cloudburst could cause depends heavily on the terrain that is receiving the downpour. For instance, in hilly or mountainous terrain, the water can accumulate in stream beds or canyons and cause deadly and damaging flash flooding.

Cloubursts often look like streams of water falling from the sky instead of just drops.

Here are some of the world's most devastating cloud bursts:

- On 24 Aug, 1906, Guinea, Virginia in USA received 9.25 inches or 234.95 mm of rain in a span of 40 minutes.

- One of the fastest showers ever measured in history is that of May 1, 1908 at Porto Bello on Isthamus of Panama. 2.7 inches of rain fell in 3 minutes.

- On May 12, 1916, Plumb Point, Jamaica received 7.8 inches or 198.12 mm of rain within 15 minutes. It, however, failed to break the Porto Bello record.

- The record set in 1908 was broken on Apr 1, 1926 at Opid's camp in the San Gabriel mountains of Carlifornia. 1.02 inches of rain equivalent to 115 tons of water per acre fell in one minute.

- The next devastating cloudburst was reported on 7 Jul, 1947, when in 20 minutes, 8.1 inches or 205.74 mm of rain lashed Curtea-de-Arges, Romania.

Then 26 Nov, 1970, Barot, Himachal Pradesh, India received 1.5 inches or 38.10 mm of rain in just one minute.

- On Aug 5, 2010 night a series of cloudbursts hit India's Himalayan town of Leh, during which, unconfirmed reports say that, as much as 2 mm of rain was received within minutes.

Interesting fact:

Nebraska Toadstool Park in US is a standing example of what cloudbursts can do to a hillside. According to Popular Mechanics, heavy rains have sculpted unusual formations in the Bad Lands of Nebraska.