Traditional Culture Encyclopedia - Weather inquiry - How to know the weather

How to know the weather

gather data

The most traditional data are data such as air pressure, temperature, wind speed, wind direction and humidity collected by professionals, enthusiasts, automatic weather stations or buoys on the ground or at sea. The World Meteorological Organization coordinates the timing of these data collections and sets standards. These measurements are made every hour (METAR) or every six hours (SYNOP).

Data from meteorological satellites are becoming more and more important. Meteorological satellites can collect data from all over the world. Their visible photos can help meteorologists study the development of clouds. Their infrared data can be used to collect the temperature of the ground and cloud top. By monitoring the development of clouds, we can collect the wind speed and direction at the edge of clouds. However, because the accuracy and resolution of meteorological satellites are not good enough, ground data is still very important.

Data assimilation

In the process of data assimilation, the collected data are combined with the numerical model used for prediction to produce meteorological analysis. The best estimate of its atmospheric state is the three-dimensional representation of temperature, humidity, air pressure, wind speed and wind direction.

Data weather

According to the results of physics and fluid mechanics, the change of atmosphere with time is calculated.

Output processing

The original output of model calculation generally needs to be processed to become a weather forecast. These treatments include using statistical principles to eliminate the deviation in known models or making adjustments with reference to the calculation results of other models.

Important tool

The important tool of weather forecast is weather map. Weather maps are mainly divided into ground and high altitude. The weather map is densely covered with various weather symbols, which are filled in after being translated according to meteorological codes all over the country.

Each symbol represents a particular weather.

The symbols representing clouds are Cirrus, cirrocumulus, cirrostratus, Altocumulus, nimbostratus, Cumulonimbus and so on.

Symbols representing weather phenomena include: thunderstorm, tornado, fog, continuous heavy rain, light snow and light showers.

In addition, there are symbols indicating the change of wind direction, wind speed, cloud cover and air pressure.

All these symbols are filled in their respective geographical positions in a unified format. In this way, meteorological elements such as wind, temperature, humidity, air pressure, clouds, cloudy, sunny, rain and snow observed at the same time in a wide area can be filled in a weather map. So as to form weather maps representing different times. With these weather charts, forecasters can further analyze and process them, and express the analysis results with lines and symbols of different colors.

The analysis content of the ground weather map includes: drawing the regional scope of important weather phenomena (such as precipitation, gale, blizzard, etc.). ), draw the positions of cold front, warm front and quasi-static front, draw the isobar of the whole picture, and mark the center and intensity of low pressure and high pressure. Through this analysis, we can clearly see the atmospheric pressure at that time: where is the high pressure, where is the low pressure, and where is the confrontation zone between cold and warm air.

The meteorological element filled in the high-altitude weather map is the height of each point on the same isobar surface, so the contour lines separated by a certain value are analyzed and drawn. After the contour line is drawn, we can see the pressure situation at that time: where is the trough of low pressure and where is the ridge of high pressure. Then draw an isotherm and mark the cold and warm center. From the configuration of heating and cooling center, low pressure trough and high pressure ridge, forecasters can make a general judgment on the future air pressure situation.

With the development of meteorological science and technology, some meteorological stations have used advanced detection tools and forecasting methods such as meteorological radar, meteorological satellites and electronic computers to improve the level of meteorological forecasting and achieved remarkable results. It is reported that since 1966, typhoons in tropical oceans around the world have almost never escaped the "eyes" of meteorological satellites. Satellite cloud images play an important role in monitoring and early detection of severe storms and severe disastrous weather.