Weather classification

Weather charts are generally divided into three categories: ground weather charts, high-altitude weather charts and auxiliary charts. According to its nature, it can be divided into: ① scene analysis diagram. A weather map drawn according to actual observation records. ② Forecast chart. According to the results of weather analysis or numerical weather forecast, draw the weather situation forecast map or weather distribution forecast map for the next 24, 48 and 72 hours. ③ Historical weather map. An analysis chart of historical data printed and published according to the actual situation. In addition, according to the needs, it is sometimes possible to draw the average distribution map and the abnormal distribution map of the average value of a meteorological element in different time periods (such as ten days, months and years). There are thermodynamic charts, profiles, variable diagrams, etc. ① Thermodynamic diagram. According to dry air adiabatic equation and wet air adiabatic equation, this diagram is also called adiabatic diagram. This drawing is generally printed with isobar (ordinate), isotherm (abscissa), dry insulation hot line (equipotential temperature line), wet insulation hot line (equipotential temperature line) and equal saturation ratio wet line. By filling the map with the records of air pressure, temperature and humidity at various heights of a station, we can analyze the atmospheric stability over the weather station or calculate various physical quantities representing the characteristics of large temperature and humidity.

2 introduction. It is used to analyze the vertical distribution of meteorological elements and the dynamic and thermal structure of the atmosphere. The map is filled with the records of temperature, humidity and wind direction and speed of each standard isobar surface and characteristic layer, and is drawn with isobar, isotherm, equipotential temperature line, upper and lower boundaries of front area, etc. There are two kinds: spatial profile and time profile. The former uses the sounding data of multiple stations at the same time to express the physical characteristics of the vertical section of the atmosphere at a certain time and in a certain direction; The latter uses the continuous sounding data of a single station to show the evolution of atmospheric conditions over the station over a certain period of time.

③ Variable graphics. Also known as trend chart, it can reflect the distribution of a meteorological element in the past 12 hours or 24 hours. Commonly used transformer (high) diagram and temperature diagram. The strong variation region of large-scale meteorological elements can predict the future variation trend of the elements.

④ Single station diagram. The high-altitude wind map of single station drawn by polar coordinates can show the dynamic state of high-altitude wind near the station, such as vertical shear strength and thermal state of cold, warm and advection at each layer. There are also some graphs in which elements on the ground or at high altitude change with time and deviate from normal conditions.