Floods repeatedly disrupt lives, livelihoods, and public services across Indonesia, while available warnings do not always lead to timely action.This article shows how rainfall forecasts can become practical early actions before flood impacts escalate.Evidence from four Indonesian regions highlights that rainfall thresholds can support earlier decisions, while stakeholder engagements reveal the procedures, coordination, and community readiness needed to act on warnings.The study demonstrates that linking forecasts with clear responsibilities and prepared local systems can reduce avoidable losses, improve disaster governance, and strengthen resilience to elevating climate-related risks. Technical SummaryDespite advances in weather forecasting and flood warning systems, the operational translation of early warning into anticipatory action remains limited in Indonesia.This gap constrains the effectiveness of disaster risk reduction, particularly in regions exposed to recurrent hydrometeorological hazards.To address this challenge, historical rainfall, flood occurrence, and impact records from Gresik Regency, Samarinda City, South Barito Regency, and Medan City were analyzed using Log Pearson III return-period estimation and cumulative distribution functions to identify locally relevant trigger thresholds.The results indicate that rainfall exceedance levels around the 90th, 95th, and 99th percentiles provide technically credible benchmarks for preparedness escalation and resource mobilization, with marked variation across hydro-climatic settings.Stakeholder consultations further reveal that forecasting information is increasingly available, but implementation shall be supported by standard operating procedures, systematic communication pathways, functional role clarity, and sufficient local validation mechanisms.An operational framework is proposed that links forecast thresholds, impact monitoring, verification processes, and pre-defined actions.The findings provide evidence for embedding forecast-based action within decentralized disaster governance systems in Indonesia and comparable flood-prone settings of other countries.
Perdinan et al. (2026) studied this question.