Tropical cyclones rarely form over the Strait of Malacca, a narrow waterway that separates Peninsular Malaysia from the Indonesian island of Sumatra. However, in November 2025, meteorologists were shocked to witness Cyclone Senyar intensify into a tropical depression, with just the second documented case of such an event occurring in the strait.
As Cyclone Senyar made landfall on Sumatra, it brought torrential rains that dropped nearly 400 millimeters (16 inches) across many areas. The slow-moving storm passed over Sumatra's mountainous terrain, causing extensive flash floods and landslides. Streams and rivers rapidly overflowed with sediment-laden, debris-filled waters that swept through villages, cities, and towns.
Indonesian authorities reported several hundred deaths and more than 700,000 displaced people as of December 4. The abundance of loose piles of timber in the region made it difficult for the authorities to cope with the devastating impact of high water. Other tropical cyclones and monsoon rains hitting Sri Lanka, Thailand, Malaysia, and Vietnam at roughly the same time have also caused extensive destruction in the broader region.
According to one estimate from the United Nations Office for the Coordination of Humanitarian Affairs, flooding has affected more than 10.8 million people in the region and displaced over 1.2 million. The impact of Cyclone Senyar serves as a stark reminder of the importance of preparedness and disaster response measures in the face of extreme weather events.
The OLI-2 on Landsat 9 captured an image of flooding in Aceh and North Sumatra provinces, showcasing the devastating effects of Cyclone Senyar. Muddy sediment-filled water has swamped much of Lhoksukon, a town of 40,000 people, and several surrounding villages.
As Cyclone Senyar made landfall on Sumatra, it brought torrential rains that dropped nearly 400 millimeters (16 inches) across many areas. The slow-moving storm passed over Sumatra's mountainous terrain, causing extensive flash floods and landslides. Streams and rivers rapidly overflowed with sediment-laden, debris-filled waters that swept through villages, cities, and towns.
Indonesian authorities reported several hundred deaths and more than 700,000 displaced people as of December 4. The abundance of loose piles of timber in the region made it difficult for the authorities to cope with the devastating impact of high water. Other tropical cyclones and monsoon rains hitting Sri Lanka, Thailand, Malaysia, and Vietnam at roughly the same time have also caused extensive destruction in the broader region.
According to one estimate from the United Nations Office for the Coordination of Humanitarian Affairs, flooding has affected more than 10.8 million people in the region and displaced over 1.2 million. The impact of Cyclone Senyar serves as a stark reminder of the importance of preparedness and disaster response measures in the face of extreme weather events.
The OLI-2 on Landsat 9 captured an image of flooding in Aceh and North Sumatra provinces, showcasing the devastating effects of Cyclone Senyar. Muddy sediment-filled water has swamped much of Lhoksukon, a town of 40,000 people, and several surrounding villages.
Ugh, this is just getting worse & worse... Cyclone Senyar's destruction in Indonesia is absolutely brutal! 700k displaced? hundreds dead? 10.8 million affected? How can they even prepare for this?! They need better early warning systems & evacuation plans ASAP! 
And it's not like they're the only ones hit by these tropical cyclones... Sri Lanka, Thailand, Malaysia, and Vietnam are also getting slammed 
, can't believe what's happening in Indonesia 
... cyclone senyar is like, whoa! 
it's crazy that it formed over the strait of malacca 
. and 400mm of rain in one go? 
that's like, a lot! 
poor people caught in the floods, my heart goes out to them 
. but at the same time, i guess this is kinda good for climate research 
, scientists are gonna be all over this to learn from it 
and help us become more prepared for these kinds of events 
. fingers crossed that everyone gets through this okay 
.
. I'm seriously worried about all these people who've lost their homes and livelihoods - over 700k displaced, that's just insane 
We should really focus on preparing our kids for such disasters, like creating a family emergency plan & having a disaster kit ready. Every second counts when it comes to responding to such situations 
anyway, i guess the good news is that ppl r coming together to help each other out. saw some vids of ppl helping with search ops, distributing food & water... it's heartwarming to see humanity shine through all this destruction 
.
, just think about all that rain falling on Sumatra in one go... like, what's the point of having satellite imaging technology if we can't use it to predict this kind of thing? 
and 10.8 million people affected 
Cyclone Senyar is a harsh reminder of the power of nature and how we need to be more prepared for these disasters. I'm all about mindfulness and self-care but in situations like this, it's not enough 
The response from the authorities and the international community has been really impressive, especially considering the scale of the disaster. It's crazy that a tropical cyclone rarely forms in the Strait of Malacca, but thankfully it's not going to deter us from taking action.