However, under clear skies, huge tornadoes appeared in Wan Li and Tangshan. How did this phenomenon come about?

A rare giant tornado appeared in Qianxi County, Tangshan City, Hebei Province. Witnesses said that the tornado rose from a soil slope, and the huge black whirlwind was in sharp contrast with the clear sky like a column of smoke. However, the Qianxi County Emergency Management Bureau later said that it had not received any reports about tornado weather. The staff of the Meteorological Bureau also said that no tornado weather was detected that day. In fact, what happened in Qianxi County was not a tornado, but a dust phenomenon.

Although sandstorms are a bit like tornadoes, they are formed for completely different reasons. Sandstorms usually occur on land. Because of the high surface temperature, the rising temperature suddenly drops, and unstable air masses will be produced between cold and warm air currents. When the hot air mass meets the cold air mass, there will be strong convective air pressure, and the hot air mass will circularly push the cold air mass to produce a strong updraft, and dust and dirt will be rolled up in the updraft to form a sandstorm. Sandstorms don't last long, but usually disappear in a few minutes. The height rarely exceeds 100 meters, and the common sandstorms are basically between a few meters and dozens of meters. The stability of sandstorm is also poor, and it will be affected by the surrounding airflow, sometimes strong and sometimes weak.

Although the destructive power and influence of sandstorm is far less than that of tornado, its instability is also great, which will be influenced by climate and environment and become powerful. 20 16 In late April, a sports meeting was being held in a primary school in Guazhou, Gansu Province, and a sandstorm appeared on the playground, instantly throwing a third-grade pupil into the air and throwing him to the ground. Fortunately, no serious injury was caused, 20 14. Holguin Ranch in Manzhouli City was caught in a dusty weather, and the power cord of the Ranch was caught, so the generated electric spark quickly ignited the pasture hay, and the fire soared under the action of wind, forming a rare phenomenon of fire dust roll. Fortunately, the rescue was timely and did not lead to serious consequences.

If you encounter dusty weather, try not to get close to it, stay away from trees, billboards and other places that are easy to cause falling objects, find shelter and wait for the dust wind to disappear.