"The northeast monsoon is less predictable but no less consequential than the southwest monsoon." Discuss this with reference to forecasting limits and El Niño.

The northeast monsoon (NEM), or retreating monsoon, brings October–December rain to five subdivisions of South Peninsular India. It supplies about 30% of the region's annual rainfall and about 48% of Tamil Nadu's [1]. Its total volume is smaller than the southwest monsoon's (SWM), but it is harder to forecast and just as important regionally.

Why the NEM is less predictable

• Wide "normal" band: IMD calls a season normal if rain falls anywhere between 88% and 112% of the LPA (~334 mm) [1]. That range is too broad to guide planning.
• Atmospheric noise: IMD itself says that seasonal predictability is limited by strong day-to-day variability, disturbances in the tropical easterlies and the Madden-Julian Oscillation [1].
• Season totals hide extreme spells: In 2015, radar recorded rain at 100–200 mm/hour, which is cloudburst intensity, over Chennai [2]. No seasonal outlook captures that.
• Shorter forecasting history: IMD has issued NEM outlooks only since 1998 [1].

The El Niño factor

• El Niño usually weakens the SWM, but IMD notes that ENSO strongly influences year-to-year NEM variability [1].
• 2026: With a strong, strengthening El Niño and a neutral IOD, IMD expects normal-to-above-normal rain in southern Kerala and Tamil Nadu but below-normal rain elsewhere [1]. The same driver can bring floods to one district and drought to another.
• IMD warns that climate change will make heavy rain and dry spells more frequent and more intense [1].

Why it is no less consequential

• Agriculture and water: The NEM coincides with the region's second agricultural season. A shortfall reduces reservoir recharge, groundwater and crop output [1].
• Disaster risk: In 2015, three weather systems during the NEM inundated Chennai [2].
• Governance multiplier: CAG found that storm-drain gaps, missing links and encroachment on water bodies made the 2015 flooding worse [3].

El Niño ──► weak SWM ──► dry reservoirs, kharif stress
   │
   └──► erratic NEM ──► extreme spells (floods) + local deficits

Fig.: One driver, two-season risk for South India

The NEM's uncertainty therefore makes it more dangerous, not less important. The way forward is to combine IMD's impact-based forecasts and Doppler-radar nowcasting [1][2] with reservoir rules tied to forecasts and drainage and encroachment reforms of the kind the CAG recommended [3]. This would build the climate resilience that SDG 11 and SDG 13 call for.