Why Do Different Meteorological Agencies Issue Divergent Typhoon Track and Intensity Forecasts?
TyphoonSays·防御问答 · Typhoon knowledge · 更新 at 2026-10-11
Why Do Typhoon Tracks Seem to Change So Often?
When you check weather apps and notice discrepancies in the predicted track and intensity of the same typhoon among agencies like the China Meteorological Administration (CMA), the Japan Meteorological Agency (JMA), or the Joint Typhoon Warning Center (JTWC), there is no need for confusion. This does not mean any agency has "miscalculated"; rather, it stems from the inherent complexity of typhoon forecasting. A typhoon is a massive thermodynamic system, and its movement is jointly influenced by various atmospheric circulation systems, such as the subtropical high, the westerlies, and the monsoon trough. Imagine pushing a ball through a turbulent, ever-changing river; even slight changes in the water flow (the atmospheric environment) can cause significant deviations in the ball's (the typhoon's) trajectory. Different agencies use different numerical weather prediction models (computer-based mathematical models), which vary in their algorithms, initial data assimilation methods, and resolution when processing these complex variables. Consequently, their conclusions naturally exhibit subtle differences. Such discrepancies are particularly pronounced during the early stages of typhoon formation or during turning points. As the typhoon approaches and observational data increases, forecasts from various agencies typically converge.
Why Is Intensity Forecasting More Difficult Than Track Forecasting?
Compared to track forecasting, predicting typhoon intensity is significantly more challenging and often results in greater discrepancies. While track forecasting primarily relies on large-scale steering flows, intensity depends on the typhoon's internal core structure and micro-environmental factors such as sea surface temperature and vertical wind shear. Although there are commonalities in how typhoons are classified globally, specific criteria vary slightly among agencies. For instance, the CMA classifies tropical cyclones into six categories based on the national standard "Grades of Tropical Cyclones": tropical depression, tropical storm, severe tropical storm, typhoon, severe typhoon, and super typhoon. However, different agencies define "maximum sustained wind speed near the center" using different averaging periods (e.g., 1-minute average vs. 10-minute average). This directly leads to the same typhoon being reported at different intensity levels by different agencies at the same time. Furthermore, rapid changes such as eyewall replacement cycles and the intrusion of dry air remain difficult to capture with absolute precision using current technology, which is a primary reason for fluctuations in intensity forecasts.
How Should the General Public Respond Scientifically?
Faced with forecast uncertainty, the public should not obsess over which track is more "accurate," but rather focus on the dynamic changes in warning signals. When meteorological departments issue typhoon warnings, it indicates that disaster risks are accumulating. Please note that specific criteria for suspending classes, work, and transportation may vary by location; always refer to the latest notifications from local governments and education authorities. We recommend the following defensive strategies:
- Consult Multiple Sources and Look for Overlaps: Refer to ensemble forecasts from multiple authoritative agencies. Pay attention to the "probability circle" of potential impact, rather than focusing solely on a single center line.
- Prioritize Preparedness, Avoid Complacency: Even if the forecast track suggests the typhoon will only graze your area, its outer spiral rainbands can still bring gale-force winds and heavy rain. Inspect windows and doors in advance, clear clutter from balconies, and stock up on necessary emergency supplies.
- Follow Official Updates and Evacuate Promptly: Closely monitor short-term and immediate warnings issued by local meteorological observatories. Once a red warning or an emergency evacuation notice is received, take immediate action and avoid going outside during the peak of wind and rain.
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This article is original educational content from TyphoonSays. Please refer to the latest official announcements from local governments for policy standards.