TLDR;
This video explains the science behind cloud bursts, a dangerous weather phenomenon characterized by intense, sudden rainfall. It covers the formation of cloud bursts, including orographic lifting, adiabatic cooling, and the role of updrafts. The video also discusses the impacts of cloud bursts, such as flash floods and landslides, and emphasizes the importance of early warning systems and avoiding construction in vulnerable areas.
- Cloud bursts are defined by rainfall exceeding 100mm per hour in a localized area.
- Orographic lifting and adiabatic cooling are key factors in cloud formation.
- Updrafts within clouds suspend water droplets until they become too heavy, leading to a sudden burst.
- Early warning systems and responsible construction practices can help mitigate the impact of cloud bursts.
What is a Cloud Burst? [0:38]
A cloud burst is a meteorological event defined by extremely heavy and sudden rainfall, typically exceeding 100 mm (4 inches) per hour in a localized area. This intense downpour can lead to flash floods and landslides, posing significant risks to human life, infrastructure, and ecosystems. Cloud bursts are considered geohydrological hazards, resulting from the interaction of geological factors like terrain and soil structure with hydrological processes such as intense rainfall and water accumulation.
How Cloud Bursts Form [1:48]
Cloud bursts begin with warm, moist air being pushed upward along mountain slopes through orographic lifting. As this air rises, it expands and cools adiabatically due to lower atmospheric pressure. When the air reaches its dew point, water vapor condenses into tiny droplets, forming cumulus clouds capable of producing thunderstorms and heavy rain. Strong updrafts within these clouds suspend water droplets and ice particles, preventing them from falling. As condensation continues, the cloud becomes saturated and heavy, eventually leading to a sudden and intense burst of rainfall when the updrafts weaken or the droplets become too large to remain suspended.
Langmuir Precipitation [3:35]
The intensity of a cloud burst is amplified by Langmuir precipitation, where large raindrops collide with and absorb smaller ones as they fall, causing them to grow rapidly. This process results in a more violent and abrupt downpour, overwhelming the land's ability to absorb or drain the water. In mountainous regions, this can trigger flash floods, mudslides, and landslides, blocking roads, damaging homes, and endangering communities, wildlife, and vegetation.
Preventing Cloud Bursts [4:31]
While cloud bursts cannot be fully prevented, their impact can be reduced through early warning systems like Doppler radar, which can detect atmospheric conditions leading to cloud bursts up to 6 hours in advance. This allows time for evacuation and emergency response. It is also crucial to avoid building in low-lying or landslide-prone areas, especially in mountainous regions. During a cloud burst, it's important to stay away from rivers, drains, and flooded streets due to rapidly rising water levels.