Surface Weather Analysis - Station Model Used On Weather Maps

Station Model Used On Weather Maps

When analyzing a weather map, a station model is plotted at each point of observation. Within the station model, the temperature, dewpoint, wind, sea level pressure, pressure tendency, and ongoing weather are plotted. The circle in the middle represents cloud cover. If completely filled in, it is overcast. If conditions are completely clear, the circle is empty. If conditions are partly cloudy, the circle is partially filled in. Outside the United States, temperature and dewpoint are plotted in degrees Celsius. Each full flag on the Wind Barb represents 10 knots (19 km/h) of wind, each half flag represents 5 knots (9 km/h). When winds reach 50 knots (93 km/h), a filled in triangle is used for each 50 knots (93 km/h) of wind. In the United States, rainfall plotted in the corner of the station model are in English units, inches. The international standard rainfall measurement unit is the millimeter. Once a map has a field of station models plotted, the analyzing isobars (lines of equal pressure), isallobars (lines of equal pressure change), isotherms (lines of equal temperature), and isotachs (lines of equal wind speed) can be easily accomplished. The abstract present weather symbols used on surface weather analyses for obstructions to visibility, precipitation, and thunderstorms were devised to take up the least room possible on weather maps.