Cyclone Warnings Explained: How to Read IMD Alerts and Act in Time

A cyclone forecast is useful when people can connect it to a decision: whether to postpone a sea trip, protect a home or move to a safer place. The India Meteorological Department’s new cyclone and marine-weather decision support system, launched on October 12, brings several kinds of hazard information into one map-based platform.

IMD says the public system combines cyclone tracks and intensity with information on winds, rainfall, storm surge and rainfall over river catchments. It is intended for residents as well as disaster managers and government agencies. The launch accompanied preparations for the October–December cyclone season. IMD’s launch announcement.

Four stages, different time references

IMD’s warning sequence begins with a pre-cyclone watch, issued 72 hours in advance. It describes a developing disturbance, the likelihood of intensification and the coastal belt that may experience adverse weather.

A cyclone alert follows at least 48 hours before adverse weather is expected along the coast. It adds information about location, intensity, likely movement and potentially affected districts, together with advice for fishermen, residents and officials.

A cyclone warning is issued at least 24 hours before expected adverse coastal weather. The forecast landfall point is included at this stage, and updates describe heavy rain, strong winds, storm surge, likely impacts and recommended action.

The post-landfall outlook is issued at least 12 hours before expected landfall, despite its name. It describes the cyclone’s likely inland movement and the adverse weather that could follow. The 48-hour and 24-hour stages refer to the onset of adverse weather, which should not be confused with the moment the centre crosses the coast. IMD’s four-stage warning guide.

Read the local hazard information

A track map answers where the storm’s centre may travel. Rainfall, wind and storm-surge information answer additional questions about the hazards people may face. Reading them together is more useful than focusing only on a line across the sea or the name of the storm.

Check the issue time and the places named in the latest bulletin. An old screenshot can describe a forecast that has since changed. A household preparing for flooding and a fishing crew considering a departure also need different parts of the advice. Local evacuation instructions deserve prompt attention.

Prepare before conditions deteriorate

IMD’s preparedness guidance advises keeping drinking water, food requiring little preparation, a working radio and spare batteries ready. Secure loose outdoor objects before strong winds arrive, and account for children or adults with special dietary needs.

People in exposed low-lying areas should move early enough that routes remain usable, and act promptly when authorities order evacuation. A lull as the eye passes does not mean the storm has ended: strong winds can return suddenly. Remain in shelter until those in charge say it is safe to leave, and avoid dangling electrical wires. IMD’s cyclone preparedness guidance.