1, tropical depression: the maximum wind speed is 6 ~ 7, (10.8 ~ 17. 1 m/s).
2. Tropical storm: the maximum wind speed is 8-9, (17.2-24.4m/s).
3. Severe tropical storm: maximum wind speed 10 ~ 1 1, (24.5 ~ 32.6m/s).
4. Typhoon: maximum wind speed 12 ~ 13, (32.7 ~ 4 1.4m/s).
5. Strong typhoon: maximum wind speed14 ~15 (41.5 ~ 50.9 m/s).
6. Super typhoon: the maximum wind speed is ≥ 16 (≥ 5 1.0m/s).
Second, the matters needing attention when the typhoon comes
1. When the typhoon came, the wind was very strong. Everyone should go out less. Never walk on dams or bridges in rivers, lakes and seas. Don't drive or ride a bike in areas affected by strong winds.
2. If you see a wire blown off by the wind on the road, don't touch it with your hands or get close to it.
3, landslides and other disaster-prone areas and areas where high-intensity rainstorms have occurred, we should be vigilant and evacuate in time.
4. If dangerous buildings and accumulated water are found, contact relevant departments in time. In case of danger, follow the instructions of relevant departments and transfer safely.
5. In case of thunderstorm and strong wind, turn off the running household appliances in time and unplug them. If you accidentally get water in your house, cut off the power immediately.
6. When driving, park your car in a safe place, get off quickly, and rely on buildings to avoid typhoons. Never hide in the car to avoid the typhoon. The typhoon is coming, and the car is not safe enough to fight against it.
7. Please don't park your car in the underground garage or in a low-lying place, but try to park it in a high place. Pay attention to falling objects in parking places, beside billboards and trees, which are also dangerous areas.
8. When driving, pay attention to the depth of water. If the engine is parked in the stagnant water, please don't ignite and pay attention to the manhole cover.
Third, the conditions for the formation of typhoons
1 should be a vast atmosphere with high temperature and high humidity. The temperature and humidity of the bottom atmosphere on the tropical ocean surface are mainly determined by the sea surface temperature, and typhoons can only form on the warm ocean surface with the sea surface temperature higher than 26℃-27℃.
2. There is a primitive whirlpool. In this way, in the early stage of typhoon formation, it will not disappear because the surrounding airflow directly flows into the vortex center, so it will soon fill up and disappear. In addition, in the typhoon-generating area, the difference of wind speed between high and low airflow directions is small, which is also the main reason why it is difficult to generate typhoons above latitude 20.
3. The difference of wind speed in the vertical direction should not be too big, and the relative motion of the upper and lower layers of air is very small, so that the latent heat released by water vapor condensation in the initial disturbance can be stored in the air column in the typhoon eye area, forming and strengthening the typhoon warm center structure.
4. There should be enough geostrophic deflection force, and the rotation of the earth as a typhoon structure is beneficial to the formation of cyclone vortex. The geostrophic deflection force is close to zero near the equator and increases at the north and south poles. Typhoons basically occur on the ocean surface about 5 latitudes from the equator.
Fourth, the causes of typhoon formation
Typhoon originated in tropical ocean, where the temperature is high and a large amount of seawater is evaporated into the air, forming a low pressure center. With the change of air pressure and the movement of the earth itself, the inflow of air also rotates, forming a counterclockwise air vortex, which is a tropical cyclone. As long as the temperature does not drop, this tropical cyclone will get stronger and stronger, and finally a typhoon will form.
legal ground
Article 5 of the Notice of the General Office of the State Council on Doing a Good Job in Preventing Heavy Rainfall fully implements various flood control and hedging measures: In view of the fact that typhoons landed early this year and the number may be large, coastal areas should conscientiously improve the typhoon prevention plan, formulate emergency evacuation plans for personnel, and especially implement grassroots typhoon prevention measures, and take reinforcement measures in advance for buildings, billboards and houses with poor wind resistance. Railway, transportation, civil aviation, electric power, communication and other departments should take effective measures in time to ensure the safe and smooth transportation and communication and ensure the power supply.