Rapid intensification of tropical cyclones is challenging India's early-warning systems. Examine with reference to recent cyclones on the east coast.
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Rapid intensification (RI) is a sharp rise in a cyclone's sustained winds within about a day. On IMD's scale, a storm can jump from Severe (48–63 kt) to Very Severe (64–89 kt) or higher before warnings catch up [2]. As the Bay of Bengal warms, RI is making warning lead-time the weakest link in India's cyclone management.
How RI strains early-warning systems
- Intensity error: models forecast a storm's track better than its strength. If the forecast category is too low, fewer villages are evacuated.
- Compressed lead-time: evacuation orders, fishing bans and shutdowns depend on the forecast category. RI leaves districts hours to act, not days.
- Hidden ocean heat: satellites measure the sea surface, but the deeper warm water that feeds sudden strengthening is hard to observe.
Evidence from recent east-coast cyclones
- Amphan (2020): it intensified rapidly over 24 hours and became the first Super Cyclonic Storm over the Bay since 1999 [3].
- Arnab (2026): IMD forecast winds of 115–125 km/h, gusting to 140 km/h, for landfall day [1]. The storm reportedly grew stronger than some models predicted. It then crossed the Andhra coast hours early and at night, cutting short the evacuation window.
Gaps in the warning chain
- Delayed infrastructure: a Parliamentary Standing Committee, cited by PRS, found that some early-warning projects for Odisha and Andhra Pradesh commissioned in 2015 had not started [4].
- Last-mile alerts: under the World Bank-funded NCRMP-II, the siren target was cut from 750 to 200 [5]. Sirens matter most for a night landfall, when people are asleep.
Way forward
- Plan for the worst plausible case: IMD and INCOIS should issue probabilistic intensity forecasts. Evacuation zones should be drawn for the upper category, not only the most likely one.
- Better ocean data: feed sub-surface heat readings from buoys and Argo floats into intensity models.
- Impact-based forecasting: target shutdowns to the zones most at risk, so warnings stay credible.
- Community warning teams: Bangladesh's Cyclone Preparedness Programme has 76,000+ volunteers [6]. Its experience shows that trained villagers can act within a short warning window.
RI does not make India's zero-casualty model obsolete. It shifts the task from predicting a storm precisely to preparing for uncertainty. Combining better ocean science with community-led, last-mile warning, as the Disaster Management Act, 2005 and the Sendai Framework envisage, can protect the gains Odisha and Andhra Pradesh have made as the Bay warms.
Sources
- 1IMD, Tropical Cyclone Advisory No. 07 (based on 1800 UTC, 26 Oct 2026)Arnab forecast of 115–125 km/h gusting to 140 km/h
- 2RSMC New Delhi (IMD), Terminology on Cyclonic Disturbances over the North Indian OceanSCS and VSCS wind bands
- 3RSMC New Delhi (IMD), Press Release on Super Cyclonic Storm Amphanrapid intensification over 24 hours; first Bay of Bengal SuCS since 1999
- 4PRS Legislative Research, Demand for Grants 2021-22 Analysis: Home AffairsStanding Committee finding on stalled early-warning projects in Odisha and Andhra Pradesh
- 5World Bank, National Cyclone Risk Mitigation Project-II (P144726)siren target cut to 200
- 6UNDRR, Bangladesh: Advancing Early Warnings for AllCyclone Preparedness Programme has 76,000+ volunteers