Jakarta, December 10, 2025 — The tropical cyclone that struck the provinces of Aceh, North Sumatra, and West Sumatra, known as Tropical Cyclone Senyar, has caused extreme rainfall, flooding, and strong winds across several regions, leading to significant social and economic impacts. As of December 10, the National Disaster Management Agency (BNPB) reported 969 fatalities and 262 missing persons.

This storm is one of two tropical cyclones that have formed north of Indonesia. The phenomenon underscores Indonesia’s position within a complex hydrometeorological risk zone, highlighting the urgent need for data-driven mitigation, adaptive spatial governance, and effective crisis communication.

According to Arcandra Tahar, Board of Experts member at Prasasti Center for Policy Studies and an Indonesian energy expert, tropical cyclones that cross northern Indonesia should be understood within a long-term scientific context.

“If we examine storm track data over the past 150 years, the northern part of Sumatra and the Strait of Malacca have indeed been crossed by tropical storms. This shows that such phenomena are not a single anomaly but part of nature’s return period, which can recur every few decades,” Arcandra explained.

He added that based on the Saffir–Simpson scale, this event is classified as a tropical storm, with wind speeds in the range of 35–40 mph—stronger than a tropical depression, but not yet reaching the intensity of a typhoon or hurricane.

“To mitigate disasters under extreme conditions, we use 100-year return period meteorological and oceanographic analyses to design coastal and marine structures. This recent tropical cyclone is a reminder that Indonesia must ensure the resilience of its infrastructure, spatial planning, and emergency protocols at all levels in response to this evolving risk,” he said.

Arcandra also emphasized that climate change is only one variable that influences the impact of disasters.

“While climate change may strengthen the intensity of extreme events, local factors—such as watershed vulnerability, forest degradation, and land conversion—play a crucial role in determining impact severity. Countries accustomed to facing cyclones like Japan, Taiwan, China, and the Philippines demonstrate that spatial discipline, environmental conservation, and community preparedness are just as vital as meteorological technology.”

Nila Marita, Executive Director of Prasasti, stated that:

“The tropical cyclone hitting Sumatra shows that we are entering a new era of risk. Indonesia already has a strong early warning foundation through BMKG (Meteorological, Climatological, and Geophysical Agency). The next step is ensuring that scientific data, spatial policies, infrastructure, crisis communication, and regional preparedness operate in full alignment.”

Beyond meteorological risks, Prasasti highlighted the importance of more responsive and coordinated crisis communication.

“Technical information from BMKG must be translated into operational messages that the public can easily understand. During disasters, the speed and consistency of communication between ministries, agencies, and local governments determine the effectiveness of response,” Nila said.

She added that strengthening the functions of existing Crisis Communication Centers will greatly assist the public in accessing the latest updates, ongoing emergency measures, and timely aid.

“The effectiveness of these centers can minimize misinformation, improve coordination between authorities and communities, and reduce the risk of disinformation during emergency situations,” Nila emphasized.

Prasasti outlined several measures to complement ongoing government efforts and strengthen national resilience:

• Adopt forecasting and monitoring technologies capable of tracking tropical cyclone formation and simulating storm movement numerically.
  This technology, widely used in developed nations such as the United States to monitor hurricane direction and intensity, allows for earlier disaster mitigation.
• Integrate storm monitoring data into spatial planning and development strategies.
  Advances in meteorological technology create opportunities to link meteorological data with disaster-prone zonation and development plans at national and regional levels.
• Review infrastructure design standards based on extreme weather scenarios.
  This approach supports government efforts to ensure that vital infrastructure—such as drainage, dams, coastal protection, and ports—remains resilient against extreme events.
• Align national crisis communication protocols across ministries, agencies, and local governments, while strengthening Crisis Communication Centers at disaster sites.
  This ensures that information from various agencies can be converted into clear, consistent public instructions.
• Enhance ecosystem- and community-based mitigation.
  Restoring watersheds, protecting forests, rehabilitating coastal areas, and applying adaptive spatial planning can reduce disaster impact, particularly in evacuation and protection of vulnerable groups.
• Expand support for local governments in following up on early warnings.
  This includes developing standard operating procedures for emergency response, conducting public education and community preparedness drills, and strengthening technical capacity to translate BMKG information into rapid field action.