Plain English Meaning

The weather station can tell that something is falling from the sky, but it can't tell exactly what. So the report just says 'unknown precipitation.'

Full Definition

A METAR notation indicating that precipitation is occurring at an automated reporting station, but the station's sensors cannot identify what type it is (rain, snow, drizzle, etc.). The code is generated only by automated weather stations equipped with present-weather sensors that detect precipitation but cannot classify it.

Context Anchor

Seen in the weather section of an aviation routine weather report, called a METAR, especially from automated reporting stations.

Why Pilots Care

Signals uncertain conditions that may affect , , or and warrants checking additional weather sources.