Definition
In NEXRAD weather radar imagery, strobes are false radial lines or spikes that appear to extend outward from a radar site, caused by the radar antenna detecting non-weather sources of radio energy such as the sun, wind farms, or other transmitters. They are a known display artifact and do not represent actual precipitation.
Plain English
Strobes are fake streaks on a weather radar picture that look like they shoot outward from the radar location. They are not real weather — the radar is picking up something other than rain or snow and drawing it on the map.
Context Anchor
Seen when interpreting NEXRAD weather images and checking whether displayed returns are real weather or radar abnormalities.
Derivation
From the Greek strobos, meaning 'a whirling' or 'spinning.' The term carries over to radar because these false returns appear as straight lines radiating outward, like spokes from a spinning wheel centered on the radar site.
Why Pilots Care
Strobes dramatically improve see-and-avoid capability and are required for night operations under most regulations.
Analogy
A strobe on NEXRAD is like a bright streak in a photo caused by glare. The streak is visible in the picture, but it is not a real object sitting in the scene.
Intuition Check
Do not read “strobes” here as aircraft flashing lights. In this context, strobes are streak-like radar display artifacts on a NEXRAD image.
Example Sentence 1
The line of returns pointing straight east from the radar site at sunrise was a strobe, not a squall line.
Example Sentence 2
With the strobes illuminated, the approaching aircraft spotted the traffic from three miles away.