How a tropical system became a cyclone

Muscat, Oct 10 - The tropical system that has developed over the Arabian Sea has been keenly watched by meteorologists. The system developed into a deep depression and was later classified as a tropical storm. It has now been upgraded to a cyclonic storm. So how does a storm attain the status of a cyclone? Wind velocity at the centre (eye) determines whether or not a tropical system is a cyclone. “If the speed is more than 64 knots, we can call it a tropical Category 1 cyclone,” said Malik al Hussaini, a meteorologist from the National Multi-Hazard Early Warning Centre.

If the speed exceeds 34, then it is categorised as a tropical storm until 63 knots. If the speed is between 28 and 33 knots, it is described as a deep depression. A tropical depression has wind speeds in the range of 17 to 27 knots, while a trough has a wind speed of less than 17 knots at the centre. Experts at the Oman Met office expect Luban to intensify further in the next 48 hours into a Category 2 cyclone. In that case, it will have a wind speed of 83 to 95 knots, says Al Hussaini. Weather experts expect the cyclone to hit the Dhofar Governorate on Friday evening and last for two days, bringing with it heavy rains with waves rising to a height of 6 to 8 metres.

Lakshmi Kothaneth