How to analyze the weather situation by using weather map
1) high pressure center: the central area is generally clear, and there may be a cold front in front. There is a quasi-static stable front between the two high pressures and a warm front behind it.
2) Low pressure center: It is prone to precipitation and cloudy weather nearby, and cold and warm fronts often extends from the low pressure center, so it is often accompanied by cold and warm front weather. The ground depression is often located in front of the high-altitude trough line, which, driven by the high-altitude trough, produces precipitation weather and even thunderstorm weather.
3) Three-hour pressure change line: reflecting the change of pressure field is an important basis for analyzing the movement and intensity change of weather system, determining the front position and analyzing the front change. For example, there is a positive pressure change after the cold front and a negative pressure change after the warm front.
4) Weather phenomenon: It is often accompanied by the appearance of weather system, changing with the intensity of weather system and moving with the movement of weather system. You can learn more about some weather phenomena and common configurations of weather systems, such as low air pressure in front of the high-altitude trough and frequent precipitation; Heavy precipitation often occurs near shear lines and rapids; Precipitation and cloudy weather near the stationary front generally last for a long time; Under the control of high pressure, radiation fog often appears at night or early morning; Advection fog mostly appears in the west or southwest of subtropical high or sea level.
5) Wind: The movement of wind can drive the movement of weather system, and the temperature advection caused by wind also affects the intensity change of weather system. At the same time, wind can also bring water vapor transportation. Appropriate wind speed can provide favorable conditions for the formation of precipitation or fog, but at high wind speed, fog or clouds can be blown away, bringing sunny weather.
B, the intensity change of weather system and weather phenomenon
Because the strength of weather system affects the severity of weather phenomena, we should pay attention to the changes of weather system strength. Generally, it can be judged by the following methods:
1) Cold and warm advection: cold advection makes cold system stronger, warm system weaker, and warm advection is the opposite;
2) Positive-negative conversion: the high-voltage center becomes stronger with positive conversion, and becomes weaker with negative conversion, and the low-voltage center is opposite;
3) Analyze the weather situation of high altitude map: high altitude affects the ground, and system enhancement in high altitude map will also enhance the corresponding ground weather system. For example, the deepening of the high-altitude trough will enhance the ground low pressure and its frontal system;
4) Historical continuity rule: observe the intensity change of the same system through continuous weather charts and infer the change of the system;
C. Movement of weather system and weather phenomena
The following factors are mainly considered: 1) positive and negative transformation center: the high-voltage center moves to the low-voltage center, or a new high-voltage center replaces the original high-voltage center; 2) the motion of the corresponding system in the high altitude map; 3) The principle of historical continuity.
D pay attention to disaster weather: such as typhoon, thunderstorm, hail, squall line, etc.