Bay of Bengal Low Pressure: Kerala Weather Alert and District-Wise Rain Forecast

Residents of Kerala are advised to remain vigilant as a developing weather system in the ബംഗാള് ഉള്ക്കടലില് (Bay of Bengal) is expected to bring heavy rainfall and strong winds to the state. According to forecasts issued between September 17 and 18, 2026, the state is likely to experience varying intensities of rain through September 21, 2026, with several districts placed under yellow alerts [1].

Meteorological Progression: From Thailand to the Bay of Bengal

The current weather instability is driven by a specific sequence of atmospheric movements. A cyclonic circulation initially located over northern Thailand was projected to move into the North Andaman Sea by the evening of September 18, 2026. By the evening of September 19, this circulation was expected to intensify into a formal low-pressure area [2].

Once established, this low-pressure system is projected to move in a west-northwest direction over the next 3–4 days, eventually heading toward the coasts of South Odisha and North Andhra Pradesh. Additionally, a low-pressure trough currently exists extending from Marathwada through the Palk Strait and across Tamil Nadu and Karnataka, further contributing to the rainfall patterns in Kerala.

District-Wise Yellow Alerts (Sept 17–20, 2026)

The India Meteorological Department (IMD) has issued yellow alerts for specific districts, indicating the potential for "heavy rain." In meteorological terms, heavy rain is defined as receiving between 64.5 mm and 115.5 mm of rainfall within a 24-hour period [3]. The schedule of alerts is as follows:

Date	Districts Under Yellow Alert
September 17	Pathanamthitta, Idukki
September 18	Alappuzha, Kottayam, Idukki
September 19	Kottayam, Idukki, Malappuram, Kozhikode
September 20	Kottayam, Idukki, Ernakulam

Wind Speeds and Safety Precautions

Beyond rainfall, the weather system is expected to bring isolated lightning and strong winds with speeds ranging from 40 to 50 km/h across the state through September 21. Authorities have recommended several safety measures to mitigate risks during lightning strikes [3]:

• Seek Shelter: Move to secure buildings immediately upon seeing dark clouds and avoid open spaces.
• Secure Homes: Keep windows and doors closed during strong winds and avoid touching walls or floors.
• Electrical Safety: Disconnect power to home appliances like TVs and computers; avoid using landline telephones during lightning.
• Avoid Trees and Water: Do not stand under trees or park vehicles beneath them. Fishing and boating activities should be suspended immediately.