The tornado in Nanhai, Foshan is a weak tornado. How are tornadoes classified?

A tornado blew up in the Nanhai area of ​​Foshan. It was judged to be a tornado. There are five levels of tornadoes, from F1 to F5. F5 is the strongest tornado. . The F1 level is the smallest level among tornadoes. The wind force it generates is relatively small and is relatively common in life. As long as the wind is normal, some small F1 level tornadoes will basically be produced. The wind is not very visible to the naked eye. Easy to observe. A kind of tornado often comes and goes quickly, and basically does not have much impact on people and buildings. F2 level tornadoes have relatively high wind speeds, usually around 169 kilometers per hour to 200 kilometers per hour. Such wind speeds can lift the roof of a house, make it difficult for people to walk, and can also make people driving The train was forced to stop and had to wait until the tornado was over before moving forward to avoid risking the lives of passengers. The speed of the F3 level has reached more than 300 kilometers per hour. This speed is basically the same order of magnitude as the speed of my country's high-speed rail. It can uproot the tree roots and blow the car to the ground. If you encounter a tornado of this magnitude, try to stay indoors and do not go to open areas as it can easily be blown up. The speed of F4 level is already as high as 500 kilometers per hour, which is twice the speed of high-speed rail. Such tornadoes are relatively rare in normal times, but once they occur, the damage and scope are relatively large, and they can blow down some less-than-normal tornadoes. Sturdy buildings, some old telephone poles, etc. The F5 level is the strongest among tornadoes and the most terrifying. A speed of up to 600 kilometers per hour is equivalent to the sum of the speeds of two high-speed trains. Moreover, the diameter of such a tornado is very large, usually 1 Kilometers to about 2 kilometers. For example, an F5 tornado once occurred in the United States, which had a very serious impact on the local economy.