We have all seen the classic surface weather map with red Lâ€™s and blue Hâ€™s representing low and high pressure respectively with fronts plotted to show location and direction of movement. These surface weather maps provide the reader with a quick, easy way to interpret regional or national weather. Isoplething is the process of creating lines of equal value, like contouring on topographic maps, see Chapter 1 Essentials of Meteorology: An Invitation to the Atmosphere for a review of contouring. On surface weather maps, we create isobars, lines of equal pressure. Isobars allow us to determine locations of high and low pressure. The standard convention is to plot isobars every 1000 mb, for instance, lines would be plotted at 996 mb, 1000 mb, 1004 mb, 1008 mb and so on up or down depending on the daily values. This laboratory assignment will have you access surface weather plots in real time and conduct the analysis. Mesoscale meteorologists at the Storm Prediction Center still use hand analysis techniques for storm forecasting.