Operational windows in ports: how climate risks define the terminal schedule

An operational window at a port is the interval of safe weather conditions for berthing, unberthing and cargo handling. When the window closes, the terminal stops.

At Santos, average vessel waiting time went from 9 hours in 2019 to 20 hours in 2023 (Centronave). 84% of ships were delayed in 2024 — average 12 days of waiting (Datamar/CNT). The bottleneck is not just infrastructure. It is weather.

Every lost window hour is revenue that never returns. Demurrage in Brazil: US$ 2.3 billion in 2024 (Bain & Company / Valor Econômico).

The public forecast problem for windows

Port terminals use public weather forecasts to plan windows — with 25 km resolution and a 3 to 7 day horizon. The result:

1. The forecast covers the city, not the berth. Wind and visibility vary on a scale of hundreds of meters within the same port;

2. Lack of hazard granularity. The planner needs to know maximum wind, wave height, visibility and current — each with a different threshold;

3. No probability. The forecast says "moderate wind", but does not say: "78% probability of wind above 25 knots between 2 PM and 6 PM."

What high resolution changes

With 1 to 3 km models and historical reanalysis, the terminal receives:

1. Forecast calibrated to the coordinates of each berth — not the municipality;

2. Probability of each hazard (wind, wave, visibility, current) for the next 72 hours;

3. Early warning of window closure 48 to 72 hours in advance.

This transforms port scheduling: instead of reacting to weather that has already closed, the planner adjusts the window beforehand — gaining hours of operation that were previously lost.