Heavy rains and landslides in Himachal Pradesh have drawn attention to the phrase “cloudburst.” But what is a cloudburst and can it be predicted? Let’s get into the specifics to better comprehend this phenomena and its consequences.
Identifying a Cloudburst
A cloudburst is a strong but localised period of rain. It can occur on plains, but it is most frequent in hilly areas. However, not all episodes of intense rainfall are classified as cloudbursts.
A cloudburst is defined as rainfall of 10 cm or more within an hour, covering an area of approximately 10 km x 10 km. A cloudburst is defined as 5 cm of rain in less than a half-hour in the same place. To put this into perspective, India receives an average of 116 cm of rain every year. During a cloudburst event, a location may receive 10% of its yearly rainfall in less than an hour.
The Impact of Cloudbursts
Because of their severity, cloudbursts can cause substantial damage. The rapid deluge can cause landslides and flash floods, wreaking havoc downstream. The repercussions are most severe in mountainous locations, where the terrain magnifies the effects of heavy rain.
Frequency and occurrence
During the monsoon season, cloudbursts are relatively prevalent, particularly in Himalayan states. Their occurrence is influenced by local terrain, wind patterns, and temperature changes between air layers. True cloudbursts, on the other hand, are extremely localised phenomena, making proper measurement and recording difficult.
Predicting Cloudbursts
While meteorological authorities may forecast high rainfall events, they cannot determine how much rain will fall in a specific region. Forecasts for bigger geographic areas are more accurate than forecasts for smaller locations. Although specific cloudburst events cannot be predicted, significant to very heavy rainfall warnings are often issued several days in advance. The possibility of exceptionally heavy rainfall, which could result in cloudburst-like circumstances, could be predicted six to twelve hours in advance.
Impact and Trend
According to the Indian Meteorological Department, there is no long-term trend indicating an increase in cloudbursts. However, intense rainfall events, including cloudbursts, are becoming more common around the world. While the total amount of rainfall in India has not changed considerably, a rising share of rainfall happens in a short period of time. This means that even during the monsoon season, big rainfall events are growing more intense and are interspersed with protracted dry spells.
To summarise, cloudbursts are localised and severe downpour occurrences that can have disastrous repercussions, particularly in hilly areas. While heavy rain events cannot be predicted accurately, meteorological authorities offer warnings. The rising severity of extreme rainfall events around the world emphasises the need for improved preparedness and mitigation techniques to reduce the impact of cloudbursts and other weather phenomena.