An early warning system for tropical storms in India

Sewa Ram Kalsi
India Meteorological Department, Mausam Bahvan, Lodi Road, New Dehli, India.
Tel. : +91-11-46 11 068, Fax: +91-11-46 99 216

The cyclone warning service of the India Meteorological Department (IMD) is more than a century old. Cyclone warnings are provided by the IMD from the Area Cyclone Warning Centres (ACWCs) at Calcutta, Chennai and Mumbai, and Cyclone Warning Centres (CWCs) at Bhubaneswar, Visakhapatnam and Ahmedabad. The complete cyclone warning work is supervised and co-ordinated on a real-time basis by the forecasting division at Pune.

A Cyclone Warning Division (CWD) has been set up in New Dehli to co-ordinate and supervise the whole cyclone warning programme in the country. Information on cyclone warnings is provided on a real-time basis to the control room set up in the Ministry of Agriculture of the Indian Government. Besides other ministries and departments of the government, the CWD advises the Indian Government at the apex level. In addition, the CWD also serves as RSMC- Tropical Cyclones New Dehli.

Tropical cyclone intensity analysis is performed using the Dvorak scheme. A variety of bulletins and warnings are produced by the IMD at various levels for the benefit of mariners and the public. The IMD has also operationalised a satellite-based communication system called the "Cyclone Warning Dissemination System". State government officials have found this scheme useful, especially in rural areas.

Cyclone warning is done in two stages. The first stage warning is known as a "Cyclone Alert". It is issued 48 hours in advance of the expected commencement of adverse weather over coastal areas. The second stage warning is known as a "Cyclonic Warning" and is issued 24 hours in advance. There has been a vast improvement in forecasting techniques and cyclone warning services in recent years. Details will be presented in the extended abstract.