Once the radiosonde has passed through the baseline process successfully and the desired launch window has come (one hour prior to the desired flight time), the radiosonde is taken out to the upper-air building and launch area, and is attached to the sounding train. Since the weather station is located within 5 nautical miles of the Reno-Tahoe International Airport, the observer must call the Federal Aviation Administration (FAA) Control Tower to receive clearance for the launch. On occasion, the observer will be delayed by incoming aircraft to the airport (see picture below).
Once the observer receives clearance from the FAA, it is time to launch the weather balloon and sounding train.
Reno-Tahoe
International Airport
Reno-Tahoe International Airport view from Launch Site
www.weather.gov 
