noun
- a small balloon equipped with instruments to measure atmospheric conditions at high altitudes
Usage: meteorology; short for 'pilot balloon'
Examples
- Meteorologists launched a pibal to track wind patterns in the upper atmosphere.
- The pibal rose steadily, transmitting data about temperature and humidity.
- Weather stations use pibals to gather information before launching weather balloons.
- The pibal's trajectory helped forecasters predict the storm's movement.