How to Read Typhoon Satellite Images: What Do the Different Colors Represent?
TyphoonSays·防御问答 · Typhoon knowledge · 更新 at 2026-08-17
When a typhoon approaches, satellite imagery is often the first source of intuitive information available to the public. When you see a satellite image of “NOUL” or another typhoon, those colorful patches are not random. They represent cloud-top temperatures and cloud-layer thickness detected by weather satellites across different spectral bands. Understanding these colors can help you more accurately assess a typhoon’s strength and structure.
The Temperature Code Behind the Colors
In commonly used infrared-enhanced satellite images, colors primarily represent cloud-top temperatures. In simple terms, the colder the color appears—typically white, red, or purple—the higher the cloud tops and the stronger the convection.
- Gray-white or light blue: Usually indicates low or lower-middle clouds, with relatively high temperatures and generally weak or intermittent rainfall.
- Bright white: Indicates high-altitude cumulonimbus clouds, often accompanied by heavy rain and strong winds.
- Red, dark red, or even purple/black: These are the colors that warrant the greatest caution. They represent very high cloud tops with extremely low temperatures, indicating strong updrafts and a deep convective system. If large areas of dark red or purple appear near the eyewall, the typhoon’s core has immense energy and is potentially extremely destructive.
It is important to note that visible satellite imagery primarily reflects cloud reflectivity. During the daytime, the brighter and whiter the clouds appear, the thicker they generally are. At night, infrared imagery is needed for analysis.
Key Structures Used to Identify Typhoons
In addition to color intensity, the shape and structure of the cloud system are equally important. A mature, powerful typhoon usually has the following characteristics:
- A clearly defined eye: If a circular or elliptical area of clear or nearly clear sky—the “typhoon eye”—can be seen at the center of the satellite image, this usually indicates that the typhoon is relatively strong. The smaller and more circular the eye, the more compact the typhoon’s structure and the stronger its winds tend to be.
- Spiral rainbands: Cloud bands rotating around the center are called spiral rainbands. The denser and more orderly these bands appear, the more complete the typhoon’s moisture transport and dynamical structure.
- Central dense overcast (CDO): A large mass of thick clouds surrounding the eye. If this area is extensive and highly symmetrical, the typhoon is generally at or near its peak intensity.
If you see a typhoon’s movement speed on the real-time track map begin to slow while its core cloud area on satellite imagery continues to contract and tighten, this is often a sign that the typhoon is about to intensify or maintain a high intensity.
Scientific Preparedness: Follow Official Warnings
Although satellite imagery provides an intuitive visual reference, the general public should always base disaster-prevention decisions on official warning signals issued by meteorological authorities. Under the national standard for tropical cyclone classifications in China, typhoons are divided into six categories: tropical depression, tropical storm, severe tropical storm, typhoon, severe typhoon, and super typhoon.
When yellow, orange, or red warnings are issued, it is essential to take them seriously. Specific rules regarding school closures, work stoppages, and transport suspensions may vary by location, so follow notices issued by local governments and education authorities. Do not determine the risk level solely from the colors in satellite imagery, because rainfall distribution is also affected by terrain, peripheral circulation, and other factors. Even areas far from the typhoon’s center may experience sudden violent rain and strong winds from outer spiral rainbands.
Stay calm, promptly bring balcony items indoors, check that doors and windows are properly sealed, and stock essential supplies. These are the most practical ways to prepare for a typhoon.
Real-time typhoon tracks are available 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.