What are cloudbursts?
A cloudburst is a localised but intense rainfall activity. Short spells of very heavy rainfall over a small geographical area can cause widespread destruction, especially in hilly regions where this phenomenon is the most common.
Not all instances of very heavy rainfall, however, are cloudbursts. A cloudburst has a very specific definition: Rainfall of 10 cm or more in an hour over a roughly 10 km x 10-km area is classified as a cloudburst event. By this definition, 5 cm of rainfall in a half- hour period over the same area would also be categorized as a cloudburst.
In the recent cloud bursts and flash floods reported in Himachal Pradesh and Uttarakhand, over 20 people have been killed in destruction. Isolated areas in these two states have reported heavy rainfall during this time, triggering landslides and flash floods that have disrupted rail and road traffic, and resulted in house and wall collapses.
Delhi witnessed a partly cloudy morning on Tuesday even as the weather office predicted light rain in the city during the day. According to the IMD, the city’s minimum temperature was recorded at 27.2 degrees Celsius, one notch above normal.
In Gujarat, several villages in Vadodara, Anand, Narmada, and Bharuch districts were put on flood alert as several dams in Central Gujarat, including the Sardar Sarovar Dam in Narmada, have begun to release water, following heavy rainfall.
The Sardar Sarovar Dam recorded a water level of 135.68 metres — three meters short of its Full Reservoir Level — Tuesday evening even as the Sardar Sarovar Narmada Nigam Ltd. (SSNNL) released 5 lakh cusecs of water from 23 gates of the dam.
In Kerala, the India Meteorological Department issued an “orange” alert in the districts of Idukki, Thrissur, Malappuram and Kasargod indicating the possibility of isolated heavy to very heavy rainfall. A yellow alert was issued for all other districts except Thiruvananthapuram and Kollam.