Typhoon Champi has demonstrated how costly a storm can become even before its full impact is felt. While forecast models were still disagreeing over its exact path, authorities and businesses across East Asia were already making decisions with major operational consequences.
On 23 October 2026, most of Taiwan suspended work and classes, financial markets closed, and hundreds of flights were cancelled. Maritime transport was also disrupted, with ferry services suspended and ports across the region preparing for dangerous conditions. Yet the storm's precise trajectory remained uncertain. Some forecasts kept Champi offshore near northeastern Taiwan, while others indicated a closer approach to the island. Its subsequent movement towards Japan introduced further questions for transport operators and coastal infrastructure.
For shipping companies, ports and airlines, the challenge was not simply predicting where Champi would go. It was deciding when to act and how to prepare while the forecasts were still evolving.
Forecast uncertainty is particularly challenging when a powerful tropical cyclone begins to change direction. On 21 October, the Japan Meteorological Agency (JMA) classified Champi as a large and violent typhoon, with a central pressure of 900 hPa and maximum sustained winds of 115 knots. Forecast guidance showed considerable variation in the storm's projected path. While models broadly anticipated a turn towards the north and northeast, differences remained over the timing and position of that change, affecting the potential exposure of Taiwan, the East China Sea and southern Japan.
Taiwan's Central Weather Administration (CWA) also revised its outlook as the storm approached, reporting a westward adjustment to its projected track on 22 October and anticipating weakening as atmospheric conditions became less favourable. These changes highlight two distinct sources of uncertainty:
Track uncertainty concerns where the storm will travel. A shift of several dozen kilometres may substantially change the conditions experienced at a port, along a shipping route or across a coastal transport network.
Intensity uncertainty concerns how strong the storm will be when it reaches a particular location. Even with a reasonably well-established track, changes in wind strength and the extent of the wind field can alter the operational risk.
And a tropical cyclone is not simply a point moving across a map. Its strongest winds may extend far from the centre, often unevenly across different quadrants. That is why a single forecast line, however precise it appears, cannot tell the whole story.
The commercial cost of uncertainty
For weather-sensitive industries, waiting until a forecast becomes more certain is not always an option. A shipping company may divert a vessel early, accepting additional fuel costs and delays, or maintain its route and risk encountering hazardous conditions. A port operator may suspend loading operations, reposition equipment and adjust staffing before the storm arrives. Acting too early can mean unnecessary disruption; acting too late can expose personnel and infrastructure to serious danger.
Airlines face a similar dilemma. Cancelling flights in advance creates immediate scheduling and financial consequences, but postponing the decision can lead to more complicated disruptions as aircraft, crews and passengers become displaced. By the morning of 23 October, Taiwan had recorded 977 flight cancellations since the previous day, according to its Central News Agency. Ferry services were also disrupted, affecting 96 sailings across ten routes. The cost of a storm is therefore not limited to the physical damage it causes. It also includes the preventive measures, delays and changes to operations that organisations must manage before the full impact becomes clear.
Making forecast uncertainty visible
OpenWeather's Storm Tracker API brings together tropical cyclone information into a unified view, helping organisations assess developing storms and their potential operational impact. The service presents forecast tracks alongside information about storm intensity and affected areas, providing a clearer picture of the conditions that may influence maritime operations, transport networks and critical infrastructure. For businesses making weather-sensitive decisions, the ability to consider forecast uncertainty alongside the expected storm path can support more informed risk assessment and operational planning.
Storm Tracker API provides:
- Consensus forecast track: A combined forecast extending up to ten days ahead, including expected wind strength at forecast points.
- Uncertainty zone: A visual representation of the spread between forecast models as the prediction horizon increases.
- Storm-force wind zones: The geographical extent of dangerous winds, broken down by quadrant to account for the often asymmetrical nature of tropical cyclones.
- Individual model tracks: Available on request for teams that need to examine the differences behind the consensus.
For maritime operators, this information can support route planning and help determine appropriate safety margins. For ports, it provides additional context for assessing when facilities and operations may be exposed to hazardous winds. For airlines and other transport operators, it supports earlier evaluation of potentially disruptive scenarios.
A consensus forecast does not remove uncertainty, and model agreement does not guarantee accuracy. However, presenting the forecast together with its uncertainty helps organisations understand the limitations of the available guidance rather than treating one predicted path as inevitable.
Better decisions begin with understanding uncertainty
Typhoon Champi illustrates a fundamental challenge in weather-sensitive operations: critical decisions often have to be made before the weather forecast becomes more certain.
The most valuable forecast is not necessarily the one that presents the clearest single line on a map. It is the one that helps decision-makers understand both the expected conditions and the range of outcomes they may need to prepare for. By combining multiple forecast models, visible uncertainty and detailed wind-field information, OpenWeather Storm Tracker API helps businesses approach tropical cyclone risks with greater context. Explore the OpenWeather Storm Tracker API product page to learn more.