Definition
A horizontal layer of strong radar reflectivity that appears on weather radar at the altitude where falling snow melts into rain. As snowflakes pass through the freezing level, they become coated with a thin film of water before fully collapsing into raindrops, and these wet, partially melted flakes reflect radar energy far more strongly than either the snow above or the rain below, producing a distinct bright horizontal band on the radar display.
Plain English
A bright stripe that shows up on weather radar at the altitude where snow is melting into rain. The half-melted, water-coated snowflakes bounce radar signals back very strongly, so that layer looks brighter than the precipitation above or below it.
Context Anchor
Seen in weather radar and weather briefing discussions, especially when precipitation is falling through the freezing level.
Derivation
Called 'bright' because it literally appears brighter (more intensely colored) on a radar display than the surrounding precipitation echoes, and 'band' because it shows up as a thin horizontal layer at one specific altitude.
Why Pilots Care
It marks the freezing level, helping pilots anticipate icing, turbulence, and changes in precipitation type.
Grounding Statement
Picture snow falling from cold air into warmer air: as it starts to melt, the wet particles show up unusually strongly on radar for a short vertical layer.
Intuition Check
A bright band is not a band of sunlight or clear weather. It is a radar feature caused by melting precipitation near the freezing level.
Example Sentence 1
The forecaster pointed out the bright band on the radar cross-section to show where the freezing level was sitting that afternoon.
Example Sentence 2
During preflight we checked the bright band height to decide whether to climb above the clouds or stay below the freezing level.