The Reported Latitude and Longitude has been chosen for the best match on the RASP model topographic data to the altitude and aspect of the site. The altitude scale represents constant altitude connected with white reference lines. The pressure heights vary during the day and are represended by the near horizontal red lines. If the red line has a significant slope it indicates that the atmospheric pressure is changing dramatically over the course of the day. For reference, pressure and altitude correspond at between 26ft and 32ft /1 Hpa(mb). depending mainly on temperature and pressure, but a little bit on moisture content. This means every 10mb accounts for between 260 and 320ft and that the 850mb level is usually around 5000feet while Sea Level is 1014 ish, on average. Given today's current conditions, The colors in the background represent the "local" lapse rate at each time and altitude. Red is unstable and if it continues up off the chart it will likely mean big showers and or thudnderstorms. When the unstable region only goes a bit above launch, that means strong thermals in that region. Where the background color shows, any lift will be either lucky or induced by winds hitting the terrain. See this link for a summary of the different ways we try to measure instability.
Using Windgrams?