Why Do Different Meteorological Agencies Produce Different Typhoon Track and Intensity Forecasts?
TyphoonSays·防御问答 · Typhoon knowledge · 更新 at 2026-08-20
Why Do Different Agencies Produce Different Forecasts? Differences in Numerical Prediction Models
Typhoon track and intensity forecasts do not rely on the intuition of a single expert. Instead, they are based on numerical weather prediction models run by supercomputers. Several major meteorological agencies operate such models worldwide, including the CMA (China Meteorological Administration), the Japan Meteorological Agency, the Joint Typhoon Warning Center (JTWC), and the European Centre for Medium-Range Weather Forecasts (ECMWF). Each agency uses different mathematical models, initial data sources, and algorithmic logic.
It is much like several chefs preparing the same dish. Although they have similar ingredients (atmospheric data), their recipes (model algorithms) and cooking methods (computational parameters) differ, so the results (forecasts) naturally vary. This is especially true for typhoon intensity forecasts, which involve subtle and complex changes in factors such as sea surface temperature and vertical wind shear. Differences in how sensitive the models are to these factors can lead to substantial variations in forecast intensity. Therefore, inconsistent forecasts from different countries are a normal reflection of scientific uncertainty rather than proof that any one agency is wrong.
Key Factors Affecting Forecast Accuracy
In addition to differences among models, the characteristics of the typhoon itself are an important cause of forecast discrepancies. A typhoon is a vast, nonlinear chaotic system whose movement is influenced by various weather systems, including the subtropical high and the westerlies.
- Changes in steering flow: If the surrounding atmospheric circulation is stable, the typhoon's track is generally easier to predict. In a “saddle-shaped” pattern where multiple systems compete, the typhoon may stall, loop, or abruptly change direction, making such “sudden shifts” difficult for every model to capture accurately.
- Limitations in observational data: Despite the use of satellites and reconnaissance aircraft, real-time observations over the ocean remain limited. Minor errors in the initial data may be amplified after several days of model integration, causing later track forecasts to deviate in a “butterfly effect.”
How Should the General Public Interpret Forecasts Correctly?
When faced with different forecast tracks, the public need not become overly anxious or focus exclusively on a single line. The scientifically sound approach to disaster preparedness is to pay attention to “probability” and “range” rather than a single fixed point.
- Refer to authoritative consensus guidance: It is advisable to follow warnings issued by your country's meteorological agency. In China, particular attention should be paid to the tropical cyclone classifications and warning signals issued by the CMA. Under national standards, typhoons are divided into five categories based on the maximum average wind speed near the center at the surface: tropical storm, severe tropical storm, typhoon, severe typhoon, and super typhoon.
- Follow warning and action guidance: When meteorological authorities issue a yellow warning or higher, begin checking doors and windows and stockpiling supplies. A red warning usually indicates that urgent protective measures, such as school closures and work suspensions, may be needed. Local standards may vary, so follow the guidance issued by your local government.
- Monitor updates dynamically and allow a margin of safety: Forecast track errors increase as the forecast period extends. Prediction accuracy improves significantly when the typhoon is within 24–48 hours. Therefore, while the typhoon is still far away, it is enough to stay informed. Once it enters the warning area, strictly follow the latest instructions from local emergency management authorities.
Real-time typhoon tracks can be checked on TyphoonSays (taifengshuo.com).
This article is original educational content from TyphoonSays. Please refer to the latest official announcements from local governments for policy standards.