In a long-term effort to develop advanced airport approaches in Argentina, MITRE’s Center for Advanced Aviation Systems Development will be using an All Weather, Inc. (AWI) MetObserver Automated Weather Observing System (AWOS) to assemble a comprehensive profile of weather conditions around Chapelco Airport in Patagonia. In addition to its function as an active collection system for historical weather data, the unmanned MetObserver AWOS can provide up-to-the-minute weather data to pilots via ground-to-air radio and to air traffic personnel via interactive tower displays. The MetObserver core software was designed from the beginning to be both a real-time weather source and a reservoir of historical information. It maintains a detailed, ongoing record of weather data, which can be automatically assembled into reports for analysis and output over a number of data networks, including AFTN and ATIS. Included in the MetObserver AWOS are sensors for measuring wind speed and direction, temperature, humidity, rainfall, and barometric pressure. The Chapelco Airport system will also be outfitted with AWI’s advanced Laser Ceilometer, which can determine the height and depth of up to four layers of clouds, and a Dual-Technology Visibility Sensor for measuring both visibility and runway visual range (RVR).