Flash Floods Threaten Sumatra Again, BMKG Predicts Heavy Rain in Two Rounds in Aceh
The Indonesian Meteorological, Climatological, and Geophysical Agency (BMKG) has conveyed a hydrometeorological disaster alert for Aceh province. Through a letter numbered e.B/ME.02.04/042/KBTJ/IV/2026 addressed to the Governor of Aceh on 10 April 2026, the Class I Sultan Iskandar Muda Meteorological Station detailed the potential for heavy rain in 23 districts.
With moderate to heavy rainfall accompanied by lightning or thunder, BMKG assesses that this condition has the potential to trigger disasters such as strong winds, flooding, landslides, and other incidents.
This letter is not intended to alarm the public but rather to serve as a warning for the Aceh government to promptly strengthen mitigation measures. This is particularly relevant given that the region was recently hit by major flooding at the end of November 2025, which impacted 18 districts. Moreover, as of now, there are still 26 families enduring in displacement tents in Aceh Tamiang district due to that disaster.
Now, Aceh Tamiang is again on BMKG’s radar for potential heavy rain from 11 to 15 April 2026. During this period, other districts/cities also forecasted include Aceh Besar, Aceh Jaya, Aceh Singkil, Aceh Timur, Aceh Utara, Banda Aceh, Bireuen, Langsa, Lhokseumawe, Pidie Jaya, Sabang, and Simeulue.
Additionally, there are 10 more districts/cities also at risk of being hit by heavy rain, even in two periods, namely from 11 to 20 April. They are Aceh Barat, Aceh Barat Daya, Aceh Selatan, Aceh Tengah, Aceh Tenggara, Bener Meriah, Gayo Lues, Nagan Raya, Pidie, and Subulussalam.
Regarding the analysis of the potential, the letter explains that the study is based on forecasts of wind patterns at the 3,000-foot layer. From these observations, a wind shift and convergence of air masses have been identified in the Aceh province area.
Such atmospheric conditions act as a stage for the growth of rain clouds along the shearline and convergence zone. There, clusters of clouds develop increasingly dense, bringing the possibility of moderate to heavy intensity rain enveloping the region.
The BMKG released a 3,000-foot wind forecast map on Friday, 10 April 2026. Doc. BMKG
Indeed, on 11 April 2026, flooding and landslides struck Central Aceh district due to high-intensity rain over the past week. In a report received by the Head of the Task Force for Accelerating Rehabilitation and Reconstruction (Satgas PRR) Post-Sumatra Disaster, Muhammad Tito Karnavian, the disaster at least swept through the Bintang, Lut Tawar, Atu Lintang, and Ketol sub-districts.
The Satgas PRR acted swiftly, ensuring the presence of the state is felt among the affected communities. Under Tito’s command, the steps taken include preparing heavy equipment, conducting final data collection on impacted infrastructure, and directly monitoring the situation on the ground.
Not only that, the Satgas PRR is also planning the implementation of Weather Modification Operations (OMC) as an effort to divert rain-bearing clouds, so that rainfall intensity can be controlled and not become a recurring threat. “We must work hard again,” Tito said.
The Head of the Aceh Regional Command Post (Kaposwil) of Satgas PRR, Safrizal ZA, immediately requested local governments to prepare anticipatory measures. The target is certainly ambitious: achieving zero risk.
He believes that the accuracy of BMKG’s early warnings cannot be ignored, as their validity has been proven in previous incidents. It should serve as a collective lesson so that no party is complacent in facing disaster potential. “The zero risk target or zero risk to human life can only be achieved if all parties prepare early. Do not wait for the disaster to strike before acting,” he said firmly.
The presence of Satgas PRR aims to create a sense of security for the affected communities. This unit, established by President Prabowo Subianto on 7 January 2026, will undertake all efforts to restore community life to normal as before. (*)