An upper air plot is a graph of the data obtained from a weather balloon. This information contains important details on the thermodynamic structure of the atmosphere at a specific location. Weather balloons are routinely released twice a day around 4am and 4pm depending on the time zone of the location. Meteorologists use upper air data to analyze many details of the atmosphere. During the monsoon, atmospheric stability is an important characteristic which is calculated from these data and given in the yellow text area. Large positive values (>2000) of convective available potential energy (CAPE) are present during days with numerous thunderstorms. Additionally a direct measure of precipitable water is available, which is more accurate than the satellite and model derived values of precipitable water found elsewhere on these web pages.