What type of cloud formations are relevant in urgent PIREPs?

Urgent PIREPs (Pilot Weather Reports) are critical for safety and navigation, especially in situations that could affect flight operations. Thunderstorms, particularly embedded thunderstorms, are of significant concern because they can create severe turbulence, strong winds, hail, and even lightning hazards that can critically affect aircraft in flight.

Embedded thunderstorms are particularly hazardous as they are not always visible, obscured by clouds, yet can produce dangerous conditions for pilots operating nearby. This makes reporting such formations through urgent PIREPs essential for informing other pilots and air traffic control about current and potentially severe weather conditions.

While other cloud types such as cirrus, stratus, and cumulus can be relevant to weather conditions, they generally do not pose the same level of immediate threat to flight operations as thunderstorms do. Thus, the focus on thunderstorms in urgent PIREPs is paramount for the safety of all aircraft affected by these weather phenomena.