Torrential rains triggered by cloud bursts caused landslides and heavy floods that poured down hills in Uttarakhand, killing at least 9 people by Friday and destroying dozens of homes, officials said.
Many people were trapped under toppled houses and debris unleashed by the landslides.
Flooding water and mudslides have blocked roads at more than a dozen places delaying the movement of rescue teams in the area. Helicopters were unable to fly rescue teams due to poor visibility in the area.
Uttarakhand was badly hit by monsoon flooding and landslides in 2013, when at least 1,000 people died in the state as it experienced its heaviest rains in nearly 80 years.
Here are 4 things to know about a cloud burst.
What is a cloud burst?
Highly concentrated rainfall over a small area lasting for a few minutes to few hours is called a cloud burst. It leads to sudden flash floods and landslides in which houses collapse and ultimately results in human casualties on a large scale.
How does it happen?
Cloud bursts are manifestations of an intense whirling mass of fluid, on small scale, that generate strong currents, which lift the moisture laden air with sufficient rapidity to form dense towering vertical clouds which are capable of shedding water load with great strength and ferocity.
Why are the hilly areas more prone to cloud burst?
Steep hills favour the formation of these clouds. Also, water flowing down steep slopes bring debris, boulders and uprooted trees with great velocity, damaging any structure that comes in the way.
Can it be predicted?
There is no satisfactory technique for anticipating a cloud burst because they occur in relatively small scale. A very fine network of radars is required to detect the likelihood of a cloud burst which could be very expensive.
(With AFP inputs)