Beijing welcomes strong winds, cooling and dusty weather.

　　Xinhua News Agency, Beijing, April 20 (Reporter Ni Yuanjin) The Beijing Meteorological Bureau reported on the 20th that due to the influence of strong cold air, the Beijing area ushered in a strong wind and cooling process on the night of the 19th, accompanied by dusty weather. A blue warning signal of strong wind was issued, and the temperature dropped significantly. It is expected that this round of weather process will end on the 21st.

　　Du Jia, chief forecaster of Beijing Meteorological Observatory, said that during the day of 20th, there were 4 or 5 northerly winds and 7 or 8 gusts in Beijing. By the afternoon of 21st, there were still 3 or 4 southerly winds with 6 gusts. Affected by the upstream dust transportation and local strong winds, the dust weather began to affect Beijing on the night of the 19th, and the visibility dropped to 2-6 kilometers at the lowest.

　　The windy weather also brought about a significant drop in temperature. "The maximum temperature dropped by 10℃ to 12℃ in 48 hours. From the 20 th to the 21 ST, the highest temperature in Beijing during the day dropped to 15 C to 21 C, and the lowest temperature at night was 8 C to 12 C. " Du Jia said.

　　Sandstorm weather is divided into floating dust, sand blowing, sandstorm, strong sandstorm, extra-strong sandstorm and other different categories according to factors such as whether dust and sand on the ground are blowing and horizontal visibility. According to the Meteorological Propaganda and Science Popularization Center of China Meteorological Bureau, three conditions need to be met to form a sandstorm. First, the strong wind as the power source; Second, as the material basis, the dust source; Third, the unstable air conditions that make the dust roll higher.

　　Why do you feel windy and dusty this spring? Du Jia said that statistics show that the temperature rose rapidly in the spring of March, and the sand source areas in the north began to thaw, but there was less precipitation. At the same time, cold air activities in the north were still frequent and windy weather was frequent.

　　According to the news of China Meteorological Bureau, from 19th to 20th, due to the influence of cold air and strong wind, there were sandstorms or floating dust in southern Xinjiang basin and east, most of Inner Mongolia, Gansu, Ningxia, northwestern Shaanxi, northwestern Shanxi, northern Hebei, northern Beijing, central and western Liaoning, central and western Jilin and central and western Heilongjiang. Among them, there were sandstorms in parts of southern Xinjiang basin, western Inner Mongolia and Hexi Gansu, and there were strong sandstorms locally.

　　The meteorological department reminds that when windy and dusty weather occurs, you should stay away from tall buildings, billboards and temporary structures, and beware of falling objects. The elderly, children and people with respiratory allergic diseases should try their best to go out, and outdoor activities need to wear masks for protection.