Southern inflows at 291% of average and the October PMO

The ONS published the Monthly Operation Programme bulletin for the period from 3 to 9 October 2026. Natural Inflow Energy projections put the South at 291% of the Long-Term Average and the Southeast/Centre-West at 119%, while the Northeast stands at 68% and the North at 47%.

The tariff effect has already appeared. ANEEL triggered the green flag for October 2026, announced on 25 September, after five months of yellow flag. According to an Eixos report on the decision, the marginal operating cost in the North subsystem fell from BRL 1,866.74 to BRL 461.46 per MWh.

The asymmetry between subsystems is where risk concentrates. South at 291% and North at 47% of the average do not offset each other automatically: they depend on available transmission and on dispatch. For consumers in the free market, high inflow in the Southeast pushes the short-term price down. For hydroelectric generators in the North, inflow below half the average means delivering less than the contract provides.

A one-week forecast is not a guarantee for the quarter. In budget review, a sensitivity test between the bulletin's extremes says more than the national average, because it is the distance between South and North that reaches the result.