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Satellite image of Bay of Bengal

Photo credit: Nasa Earth Observatory

The boundaries and names shown and the designations used on this map do not imply official endorsement or acceptance by the United Nations.​

On 12/13 November 1970, the world’s deadliest tropical cyclone ‘Bhola’ killed more than 300,000 people in Bangladesh. The hard lesson learnt from ‘Bhola’ was not having an effective cyclone warning system to forewarn at risk communities. It is with this context that WMO/ESCAP Panel on Tropical Cyclone (PTC) came into existence in 1972. The panel started with six member countries and now comprises of 13 member countries from the Bay of Bengal and the Arabian Sea of the North Indian Ocean.

Over the last 50 years, the Panel has successfully tracked and monitored countless tropical cyclones from formation to landfall through cross-border collaboration, involving real-time data sharing and risk information exchange across the common ocean basin. The positive outcomes in managing two recent cyclones emphasize the panel's effectiveness:

Cyclone Mocha, the Bay of Bengal: On 14 May 2023, cyclone Mocha hit Myanmar. Accompanied by sustained winds of 180-190 km/h, violent gusts, torrential rainfall and flooding Mocha made the landfall in a most vulnerable context of compounding poverty, inequality and environmental degradation. However, the impact differed significantly from the 2008 devastation caused by Cyclone Nargis, a storm as powerful as Cyclone Mocha, which resulted in the loss of over 138,000 lives in Myanmar.

Cyclone Biparjoy, the Arabian Sea: On 26 June 2023, cyclone Biparjoy with wind speed of 140 km/h hit densely populated of India’s west coast of Gujarat State. Despite its ferocity, no casualties were recorded.

The accuracy of early warnings leading to targeted evacuations during Mocha and Biparjoy  saved tens of thousands at risk. The Regional Specialized Meteorological Centre (RSMC), within the Indian Meteorological Department, had been able to forecast these cyclones precisely four days in advance, which gave sufficient lead time for authorities to maneuver the coastal communities to safer areas. The RSMC monitors cyclones across the Northern Indian Ocean, collaborating with PTC members to provide early warning products and services for tropical cyclones with transboundary origins and impacts, spanning from Oman in West Asia to Myanmar in Southeast Asia.

From the lens of the Sendai Framework for Disaster Risk Reduction, the PTC has made substantial contributions towards building resilience to tropical cyclones (Figure 1).  Despite good progress in a few of the targets, reducing the number of affected people (B) lags, and challenges persist in addressing economic losses (C) and safeguarding critical infrastructure and services (D).

Figure 1. Contributions of the Panel on Tropical Cyclone towards achieving the Sendai targets

As the panel celebrates 50 years of its journey this month, five key imperatives are flagged for discussion:

First, riskier times ahead: Our world has more heat in the oceans and atmosphere, which can supercharge cyclones. A cyclone is a heat engine, transferring heat from warm ocean water up into colder layers of the atmosphere. More heat in the system means more intense heat engines. ESCAP analysis has identified intensifying and expanding risk hotspots in the Bay of Bengal and Arabian Sea at baseline, 1.5- and 2.0-degree warming, flagging the challenges of resilience in riskier times - informed, comprehensive and forward-looking.

Two, rapid intensification of tropical cyclones: In recent years, tropical cyclones in the Bay of Bengal (Amphan) and Arabian Sea (Tauktae) have shown a rapid intensification, complex tracks and increased curvature. Cyclone Titli (east coast of India, 2018), caused landslides and fatal flooding despite a precise early warning, resulting in over 50 casualties. Further, cyclones that intensify rapidly are difficult to forecast and can lead to forecasting errors. For accurate predictions, advanced surveillance should be deployed to detail monitoring of complex cyclone formation, and high-quality modeling frameworks should be adopted integrating ocean, atmosphere and land phenomena.

Three, impact-based forecasting (IBF): IBF narrows the gaps that exist between forecasters and the end-users. ESCAP has developed a methodology that translates cyclone track, intensity and land fall prediction into impact scenarios. Anticipatory action (AA) is central to early warning and action, intricately tied to IBF. It plays a key role in proactive measures enhancing to preparedness to mitigate the impacts of tropical cyclones. Operationalizing IBF and AA through PTC attachment training and capacity development activities is an important step forward and would see a seven-fold return on investment.

Fourth, cyclone early warnings for all: The UN Early Warnings for All Executive Action Plan 2023-2027  is based on four pillars – knowledge of risk, monitoring and forecasting, warning dissemination and communication, and preparedness for response. The effectiveness of multi-hazard early warning systems relies on each pillar and needs to be supported by policy, plans and financial mechanisms to enable its availability and accessibility. PTC@50 can take forward cyclone early warnings for all its members.

Finally, strengthening PTC architecture: The secretariat of the PTC is imperative to driving operations and should be strengthened to ensure that the panel is fully owned, funded, administered, and governed by its members. It can be built on the four pillars of cyclone early warnings, following the modality of the Early Warnings for All initiative, through its working groups. The 50th celebration provides an opportunity to rejuvenate PTC ready to manage complex cyclones in riskier times.

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Sanjay Srivastava
Chief, Disaster Risk Reduction
Madhurima Sarkar-Swaisgood
Economic Affairs Officer
Temily Baker
Programme Management Officer
Soomi Hong
Associate Economic Affairs Officer
Daisuke Maruichi
Economic Affairs Officer
ICT and Disaster Risk Reduction +66 2 288-1234 [email protected]