Chapter 7 Mini-Lab Key terms/Concepts Weather Sky Cover Cold Front Weather Map Symbols Warm Front Station Model Air Mass The purpose of this mini-lab is to understand and interpret weather data and maps. This lab will focus on surface maps and weather associated with fronts as they move across the United States. Wind Wind is plotted in increments of knots. The outer end of the symbol points towards the direction from which the wind is blowing. Speed is also measured in knots (1 knot = 1.15 mph). To determine wind speed, add up the total flags, lines and half lines illustrated in Table 7.1 under the wind column. Example: if there is only a circle over the station with no wind, the wind is calm. Sky Cover The circle at the center of the station plot reflects the approximate amount that the sky is covered with clouds (National Weather Service 2005). Refer to table 7.1. Weather A weather symbol is plotted on the station model if at the time of observation there is either rain, snow, thunder, winter precipitation, fog, or haze occurring or a condition causing reduced visibility (National Weather Service 2005). Refer to table 7.1. Pressure To interpret