Blitz Bureau
NEW DELHI: The India Meteorological Department put Odisha and Gangetic West Bengal under a red warning today. Most readers see the colour and not the definition — which is a pity, because the definition is the part that tells you what to do.
A low-pressure area formed over the north Bay of Bengal, and IMD issued a red colour warning for heavy to very heavy rainfall, with isolated extremely heavy rainfall, over Gangetic West Bengal and Odisha for today, 13 August. Those three phrases are not journalistic emphasis. They are defined quantities in IMD’s own rainfall classification, measured over 24 hours at a station: heavy rain is 64.5 to 115.5 millimetres, very heavy is 115.6 to 204.4 millimetres, and extremely heavy is anything above 204.4 millimetres. Two hundred millimetres in a day is roughly a tenth of what many Indian districts receive in an entire year, delivered in a single rotation of the earth.
The mechanism, not the mood: a low-pressure area over the north Bay of Bengal is what delivers August rain to eastern India. IMD placed Gangetic West Bengal and Odisha under a red warning on 13 August 2026.
Yellow means be updated. Orange means be prepared. Red means take action. Three words, and most people only ever notice the colour.
At a Glance
• Warning: Red, Gangetic West Bengal and Odisha, 13 August 2026
• Cause: low-pressure area over the north Bay of Bengal
• Heavy rain: 64.5–115.5 mm in 24 hours
• Very heavy: 115.6–204.4 mm
• Extremely heavy: above 204.4 mm
• IMD’s four colours: green — no action; yellow — be updated; orange — be prepared; red — take action
• “Isolated”: a minority of stations in the warning area, not the whole of it
The colour code is a graded instruction, and it is worth learning once. Green means no action is required. Yellow asks the public and the administration to stay updated. Orange asks them to be prepared — to move equipment, position teams, check drainage. Red asks them to take action, which is why a red day is when district administrations suspend school transport, hold ferry services and pre-position response teams rather than waiting for water to arrive. The word “isolated” carries information too: it tells you the extremely heavy falls are expected at a minority of the stations in the warning area, not across all of it. That is precisely why the warning is issued for a region rather than a town, and why the useful habit is to check the district bulletin rather than the state headline.
There is a larger point about August that connects this warning to the fields. Bay of Bengal low-pressure systems are not an interruption of the monsoon; they are the monsoon’s delivery mechanism for eastern and central India, and they arrive in a season that has so far been short of rain. A country that has built a genuinely capable forecasting service — India now issues district-level and increasingly block-level warnings that were not technically possible fifteen years ago — gets the benefit of it only when the last mile works. The constructive agenda is unglamorous and known: keep the colour code on the front of every district bulletin in the local language, make sure the panchayat secretary and the school headmaster get the same alert as the collector, and publish afterwards how much rain actually fell against what was forecast. Forecast accuracy improves fastest where it is audited in public.
