The Surface Analysis Chart is a computer-prepared chart that covers the contiguous 48 states and adjacent areas. The chart is transmitted every 3 hours. It provides a ready means of locating pressure systems and fronts and also gives an overview of winds, temperatures, dew points, and obstructions to vision at the time of the plotted observations. When using the chart, keep in in mind that it does not show cloud heights or tops or the expected movement of any item depicted. Using the surface analysis chart in conjunction with other information gives a more complete weather picture.