Cyclone Biparjoy: What is the ‘landfall’ of a cyclone?

Source: The post is based on the article “Cyclone Biparjoy: What is the ‘landfall’ of a cyclone?” published in Indian Express on 16th June 2023

What is the News?

The landfall process of Cyclone Biparjoy has started near Jakhau port in the Gujarat Kutch district and will continue till midnight.

What is the “landfall” of a cyclone?

Landfall is the event of a tropical cyclone coming onto land after being over water. As per the IMD, a tropical cyclone is said to have made landfall when the centre of the storm – or its eye – moves over the coast.

Note: A landfall should not be confused with a ‘direct hit’, which refers to a situation where the core of high winds (or eyewall) comes onshore but the centre of the storm may stay remain offshore.

What is the damage caused by a cyclone’s landfall?

The damage caused by the landfall will depend on the severity of the cyclone – marked by the speed of its winds. 

For Cyclone Biparjoy, classified by the IMD as a “very severe cyclonic storm”, the impact may include extensive damage to kutcha houses, partial disruption of power and communication lines, minor disruption of rail and road traffic, the potential threat from flying debris and flooding of escape routes.

How long does a landfall last?

Landfalls can last for a few hours, with their exact duration depending on the speed of the winds and the size of the storm system. 

Cyclones lose their intensity once they move over land because of a sharp reduction of moisture supply and an increase in surface friction. This means that while landfalls are often the most devastating moments of cyclones, they also mark the beginning of their end.