Observers shall be cognizant of the wind and weather conditions and expected air traffic in the vicinity of the station prior to commencing an upper-air observation. For instance, the exposure and warm-up times required for the various types of equipment must be considered and the agency guidelines determining the order in which preliminary operations are to be performed must be followed. Expendables should be periodically checked to ensure an adequate supply to maintain observations without interruption. Batteries used with the various radiosondes should be prepared in accordance with the manufacturer's instructions. 3.3.1 Balloon Inflation and Performance .
Ascent rate is affected by free lift and drag.
The amount of free lift required for producing optimum performance shall be determined before the balloon is inflated. The balloon must be sufficiently inflated to ensure successful release in the surface conditions which may exist at the time. The standard, average ascension rate should be 300 meters per minute. However, consideration should be given to how individual balloons produced by different manufacturers will perform based on their shape and thickness characteristics. Refer to manufacturer's instructions for recommended gas inflation amounts for specified ascension rates.