Definition
A standard phrase used in pilot weather reports (PIREPs) of icing or turbulence indicating that the reporting pilot cannot determine or classify the intensity of the encountered condition. It signals to ATC and forecasters that the phenomenon is present, but the pilot is not categorizing it as light, moderate, severe, or extreme.
Plain English
When a pilot reports icing or turbulence but does not feel able to say how strong it was, this phrase is used to record that the intensity is not being specified.
Context Anchor
Seen in aviation weather reporting guidance and weather observations when a station can detect a condition but cannot assign its intensity.
Why Pilots Care
Prevents inaccurate intensity claims that could mislead controllers or other pilots about actual flight conditions.
Grounding Statement
Picture a station that can tell rain is present, but cannot tell whether it is light, moderate, or heavy.
Intuition Check
Unknown does not mean weak, harmless, or absent. It means the reporting source cannot say how strong the condition is.
Example Sentence 1
The pilot encountered light bumps that built quickly into something harder to characterize, so the PIREP was filed with intensity as unknown.
Example Sentence 2
When filling out the PIREP form, the observer marked the turbulence section to report intensity as unknown.