Definition
A logarithmic unit used by weather radar to express how strongly precipitation reflects the radar's signal back to the antenna. Higher dBZ values indicate larger and more numerous precipitation particles, which generally correspond to heavier rainfall, hail, or more intense storms. On standard NEXRAD displays, dBZ values are color-coded, with light rain typically shown around 20 dBZ and severe thunderstorms exceeding 50 dBZ.
Plain English
A number on the weather radar that tells you how heavy the precipitation is. The higher the number, the bigger and more intense the rain, snow, or hail in that area.
Context Anchor
Seen on weather radar images and radar observation products, often tied to the colors showing precipitation intensity.
Derivation
The 'dB' part is decibels — a logarithmic scale used in many sciences to compress a huge range of values into manageable numbers. The 'Z' is the radar reflectivity factor, a measurement of how much radar energy bounces back from precipitation. Combining them gives a compact way to describe a very wide range of precipitation intensities on a single scale.
Why Pilots Care
Helps pilots judge storm severity and decide on safe routing around heavy precipitation that may bring turbulence or reduced visibility.
Grounding Statement
On a radar picture, dBZ is the strength of the weather echo: weak echoes show lighter precipitation, while strong echoes show more intense weather.
Intuition Check
dBZ does not mean a noise level, even though “decibel” is often used for sound. Here it means the strength of a weather radar return.
Example Sentence 1
The briefer pointed to a band of 45 dBZ returns along the route and recommended a deviation north of the line.
Example Sentence 2
Pilots check dBZ values on weather radar to avoid areas of intense precipitation during flight planning.