Which condition requires soliciting PIREPs?

Soliciting Pilot Reports (PIREPs) becomes particularly critical when ceilings are at or below 5,000 feet. This condition often indicates lower cloud bases, which can impact a pilot's ability to navigate and approach an airport safely. At this altitude, pilots may be more prone to encountering turbulence, low visibility, and challenging weather conditions that can significantly affect their flight path and overall safety.

When ceilings drop to this level, it is essential for air traffic controllers and weather service personnel to gather firsthand reports from pilots who are actively flying in the vicinity. These reports can provide valuable, real-time information about weather phenomena such as turbulence, cloud conditions, and the actual visibility experienced in flight. This information helps to mitigate risks not only for those pilots but also for others operating in the same airspace.

The other choices do not represent conditions that necessitate PIREPs. For example, ceilings above 10,000 feet generally indicate clear skies conducive to safe flight, while good visibility (greater than 5 miles) and low wind speeds also suggest stable flying conditions where PIREPs are less critical.