What Do the Colored Lines, Circles, and Probability Cones on Typhoon Track Maps Mean?
TyphoonSays·防御问答 · Typhoon knowledge · 更新 at 2026-08-03
Understanding Track Lines: Color Indicates Intensity, Not Danger Level
On real-time typhoon track maps, the winding colored line represents the movement trajectory of the typhoon's center. Many people mistakenly believe that red indicates the highest danger level, but this is not the case. The color of this line primarily corresponds to the maximum wind speed near the typhoon's center, based on the National Standard for Tropical Cyclone Classification issued by the China Meteorological Administration (CMA).
Typically, the logic behind the color changes is as follows:
- Blue or Green: Represents a tropical depression or tropical storm, with relatively weak winds.
- Yellow or Orange: Represents a severe tropical storm, with gradually strengthening winds.
- Red, Dark Red, or Purple: Represents a typhoon, severe typhoon, or even super typhoon, indicating extremely strong winds near the center.
It is important to note that the color only reflects the intensity at the center point "at this moment" or "at the predicted time," and does not directly equate to rainfall or destructive power in your specific area. Even if the line shows a weaker color, if its outer spiral rainbands sweep over your city, it can still bring heavy rain and strong winds. Therefore, do not just focus on the color; pay closer attention to local warning signals issued by forecasters.
Decoding Circles and Cones: Safety Boundaries Amidst Uncertainty
Besides the track line, the most noticeable features on the map are the expanding "circle" and the trumpet-shaped "probability cone."
Meaning of the Circle:
This circle usually indicates the radius of the typhoon's Force 7 wind circle (where wind speeds reach 13.9-17.4 m/s). If your location is within this circle, you may experience strong winds capable of moving tree branches and making walking difficult. As the typhoon intensifies or weakens, the size of the circle will change accordingly. Some professional charts also use concentric circles of different colors to mark the Force 10 and Force 12 wind circles, helping you judge the extent of the core destruction zone.
Meaning of the Probability Cone:
The "trumpet-shaped" area diverging forward from the typhoon's center is called the track probability cone. It represents the range of uncertainty in meteorological experts' predictions of the typhoon's future path.
- A wider cone indicates greater divergence in judgments among various meteorological agencies regarding the typhoon's direction, or unclear guiding atmospheric flows, making prediction more difficult.
- A narrower cone indicates that path predictions are more consistent and have higher certainty.
Please remember: The typhoon center does not necessarily move along the exact center of the cone; it may well deviate toward the left or right edges. Therefore, even if your city is not on the centerline of the cone, as long as it falls within the covered area, you must prepare for typhoon defenses and avoid taking chances.
Scientific Defense: Focus on Local Warnings, Not Just the Track
Once you understand the track map, the next step is action. When a typhoon approaches, the track map only provides a macro trend. Specific disaster prevention decisions should rely on warning signals (such as Blue, Yellow, Orange, and Red warnings) issued by local meteorological departments.
- Standards for School and Work Suspensions: Regulations on automatic school and work suspensions under different warning levels vary by region. For example, some coastal cities may recommend stopping outdoor operations during a Yellow Typhoon Warning, while inland areas may have different standards. Standards may vary by location; please refer to announcements from local governments.
- Defense Priorities: Regardless of minor adjustments to the typhoon's path, the impact range of strong winds and heavy rain often far exceeds the central track. Please clear clutter from balconies in advance, check the stability of windows and doors, and stock up on necessary emergency supplies.
Real-time typhoon tracks can be queried at Taifengshuo (taifengshuo.com)
This article is typhoonsay's original copy content, and the local policy standards are based on the local government's latest release.