Why Do Typhoon Forecast Tracks and Intensities Vary Across Different Meteorological Agencies?
TyphoonSays·防御问答 · Typhoon knowledge · 更新 at 2026-08-20
Why the "Diverging Views"? Differences in Numerical Prediction Models
Typhoon track and intensity forecasts are not based on a single expert's intuition but rely on "Numerical Weather Prediction (NWP) models" run by supercomputers. Currently, several major meteorological agencies operate globally, such as the China Meteorological Administration (CMA), the Japan Meteorological Agency (JMA), the Joint Typhoon Warning Center (JTWC) of the United States, and the European Centre for Medium-Range Weather Forecasts (ECMWF). Each agency uses different mathematical models, initial data sources, and algorithmic logic.
This is akin to multiple chefs preparing the same dish: although the ingredients (atmospheric environmental data) are similar, differences in recipes (model algorithms) and cooking techniques (computational parameters) naturally lead to variations in taste (forecast results). This is particularly true for typhoon intensity forecasts, which involve subtle and complex changes such as sea surface temperature and vertical wind shear. Differences in model sensitivity can lead to significant discrepancies in predicted intensity. Therefore, when we see inconsistent forecasts from different countries, this reflects the normal "uncertainty" inherent in scientific calculations, rather than indicating that one party is necessarily wrong.
Key Factors Affecting Forecast Accuracy
In addition to differences in the models themselves, the characteristics of the typhoon are also a major cause of forecast deviations. A typhoon is a massive nonlinear chaotic system, and its movement is influenced by the combined pull of various weather systems, such as the subtropical high and the westerlies.
- Changes in Steering Flow: If the surrounding atmospheric circulation is stable, the typhoon's path is usually easier to predict. However, if it is located in a "saddle field" where multiple systems interact, the typhoon may stall, loop, or suddenly change direction. Such "abrupt changes" make it difficult for all models to capture accurately.
- Limitations of Observational Data: Although we have satellites and reconnaissance aircraft, real-time observation points over the ocean remain limited. Minor errors in initial data can be amplified after days of integration calculations, leading to deviations in later track forecasts similar to the "butterfly effect."
How Should the General Public Interpret Forecasts?
Faced with different predicted tracks, the public should not be overly anxious nor focus solely on a single line. A scientific approach to disaster prevention involves focusing on "probability" and "range" rather than a single "fixed point."
- Refer to Authoritative Comprehensive Advice: It is recommended to rely on warnings issued by your national meteorological department. In China, pay close attention to the tropical cyclone classifications and warning signals issued by the CMA. According to national standards, typhoons are classified into five categories based on the maximum average wind speed near the center at the lowest level: Tropical Storm, Severe Tropical Storm, Typhoon, Strong Typhoon, and Super Typhoon.
- Follow Warning Action Guidelines: When meteorological departments issue yellow warnings or higher, you should begin checking windows and doors and stockpiling supplies. If a red warning is issued, it usually means emergency defensive measures such as school and work suspensions are required. Please note that standards may vary by location; always follow the guidelines issued by local governments.
- Dynamic Tracking and Allow for Margin of ErrorForecast accuracy improves significantly 24–48 hours before the typhoon approaches. Therefore, when the typhoon is still far away, simply stay informed; once it enters the alert range, strictly follow the latest instructions from local emergency management departments.
Real-time typhoon tracks can be queried at TyphoonSays (taifengshuo.com)
This article is typhoonsay's original copy content, and the local policy standards are based on the local government's latest release.