IMD: Kerala to see slight rainfall revival; yellow alert for four districts on Aug 18
The Hindu reports the IMD expects a modest uptick in Kerala rainfall over the next four days due to a Bay of Bengal system. A yellow alert has been issued for Kasaragod, Kannur, Ernakulam and Kottayam for Aug 18, warning of isolated heavy rainfall.
Key takeaways
- A low-pressure system in the Bay of Bengal has consolidated into a depression near coastal West Bengal and nearby areas.
- The system is forecast to move northwestward across several eastern regions within 24 hours.
- Kerala is expected to experience a slight increase in rainfall over the next four days due to inbound westerly winds.
- Kasaragod, Kannur, Ernakulam and Kottayam have a yellow alert for Aug 18 with the possibility of isolated heavy rainfall.
What Happened
The India Meteorological Department (IMD) issued a weather bulletin on Monday, August 17, 2026, indicating a low-pressure area in the northwest Bay of Bengal has consolidated into a depression over coastal West Bengal and nearby areas of Bangladesh and the northwest Bay of Bengal. The system is expected to move north-northwestwards first, then northwestwards across Gangetic West Bengal, Jharkhand and Bihar during the next 24 hours. As a result, light to moderate westerlies and northwesterlies are anticipated over Kerala and Lakshadweep in the lower tropospheric level, which is forecast to slightly enhance rainfall in Kerala over the following four days. A yellow alert has been issued for four districts in Kerala on Tuesday, August 18, due to the possibility of isolated heavy rainfall.
The bulletin specifies that the affected districts are Kasaragod, Kannur, Ernakulam and Kottayam, each warned for the potential of isolated heavy showers on the specified date. The forecast is tied to the behavior of the Bay of Bengal system and its influence on Kerala’s lower-tropospheric wind patterns, which can drive rainfall activity in the region.
Why It Matters
The forecast signals a temporary revival in rainfall for Kerala after a period of weaker monsoon activity. The expected shift in wind patterns linked to the Bay of Bengal system could influence district-level rainfall intensity, potentially affecting agrarian activity, drainage and water management, and local travel plans on the day of the yellow alert.
Background
The IMD bulletin describes a developmental sequence starting with a low-pressure area in the northwest Bay of Bengal, which has consolidated into a depression over coastal West Bengal and adjacent zones in Bangladesh and the northwest Bay of Bengal. The movement described suggests a north-northwestward track followed by a northwestward progression across several eastern states before indirect effects reach Kerala's weather patterns, mainly in the form of westerly and northwesterly winds in the lower troposphere that can modulate rain chances in Kerala.
Key Facts
- IMD issued a bulletin on August 17, 2026.
- A low-pressure area in the northwest Bay of Bengal has consolidated into a depression over coastal West Bengal and adjoining Bangladesh/bay of Bengal areas.
- The system is expected to move north-northwestwards and then northwestwards across Gangetic West Bengal, Jharkhand and Bihar in the next 24 hours.
- Under its influence, light to moderate westerlies and northwesterlies are expected over Kerala and Lakshadweep in the lower tropospheric level.
- Rainfall in Kerala is forecast to slightly increase over the next four days.
- A yellow alert is in effect for Kasaragod, Kannur, Ernakulam and Kottayam on August 18, with a warning of isolated heavy rainfall.
- Publication time: 02:13 pm IST on August 17, 2026.
What Happens Next
The bulletin indicates the weather pattern will continue to be monitored over the next 24 hours as the system moves. Authorities may revise rainfall advisories based on real-time observations, and residents in the four warned districts should stay alert for updates and take precautions against potential isolated heavy rainfall on August 18.
Sources reviewed
Project Chintan independently synthesized and analyzed information cross-checked across the sources listed above.
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