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Weather radar colors are a display convention for radar measurements, not a universal weather legend. In a base-reflectivity image, the radar sends energy into the atmosphere and measures energy returned by targets in the beam. The reflectivity value is commonly expressed in dBZ, and a color table turns ranges of those values into something a person can scan quickly.
Reflectivity first, color second
NOAA describes reflectivity as the amount of transmitted radar power returned to the receiver. Larger reflectivity values mean a stronger return. A display may map lighter returns to cooler colors and stronger returns to warmer or more vivid colors, but the actual palette belongs to the product or application. Green on one display should not be assumed to equal the exact same dBZ range or precipitation rate on another.
That is why a WxUp.TV radar color should be read as a visual representation of return strength within the selected product. If you need the precise numeric meaning of a color, use the legend supplied with the underlying radar product rather than a memorized color rule.
Why strong reflectivity is not a hazard label
A stronger return can be associated with heavier precipitation, and high reflectivity within a thunderstorm can be meteorologically important. But the color itself does not prove a particular rain rate, hail size, wind speed, tornado, or level of danger at your location. Forecasters use additional radar products and other observations to diagnose hazards.
The same caution works in the other direction. A less dramatic-looking base-reflectivity image does not guarantee that a location is safe. Some hazards are not represented well by reflectivity alone, and the beam can be sampling well above the surface.
Radar can return energy from more than rain
Weather radars detect targets that reflect energy, not only raindrops. Snow and ice particles, hail, birds, insects, ground objects, and other targets can contribute to returns depending on the scan and situation. Modern dual-polarization radar gives forecasters more information for distinguishing types of targets, but a simple base-reflectivity color is still only one measurement shown in one way.
Why the same storm can look different
- Distance: the beam is higher above the ground farther from the station, so two radars can sample different parts of the same storm.
- Product choice: base reflectivity and composite or other radar products summarize different scans or calculations.
- Display palette: websites, apps, and official products can use different color tables for similar data.
- Coverage conditions: terrain, blockage, maintenance, and data availability can alter the picture.
- Storm evolution: a loop can change rapidly as precipitation develops or weakens between scans.
A better way to use color in a loop
Begin with the selected station and timestamp. Then watch several frames and follow the shape and motion of the returns. Use color to compare relative strength within that same display, and look for consistent strengthening or weakening rather than over-interpreting one frame. If the situation matters for safety or travel, move from the visual clue to official alerts and forecasts.
A useful question is not simply “What does red mean?” but “What does this return represent in this product, how is it changing, how far is it from the radar, and what do the official products say about the same area?” That sequence keeps the color in its proper context.
Primary references and further reading
For primary technical background, see NOAA JetStream's Radar Images: Reflectivity and NOAA's How radar works. WxUp.TV's loop-reading guide and radar limitations explain how these ideas affect the station viewer.
For official weather warnings and safety instructions, use weather.gov and local emergency management sources. A radar color is context, not an all-clear or an emergency instruction.