受强冷空气影响，20日至22日北方地区有沙尘天气

Core Viewpoint - The article discusses the impact of strong cold air on various regions in China, leading to sandstorm weather from February 20 to 22, with specific areas experiencing sandstorms and even severe sandstorms [1]. Group 1: Regional Weather Forecasts - In the Beijing-Tianjin-Hebei region, most areas will have good atmospheric diffusion conditions, but the southern part may experience intermittent haze. Dust or floating dust weather is expected on February 21 and 22 due to cold air winds [1]. - The Yangtze River Delta region will also have good atmospheric diffusion conditions, with only the northern part experiencing intermittent haze. The central and northern areas will be affected by upstream sand dust transmission on February 22 and 23 [2]. - In the Fenwei Plain, most areas will have good atmospheric diffusion conditions, with intermittent haze in the central and southern parts. Dust weather is expected on February 21 and 22 [3]. - The Central China region will have good atmospheric diffusion conditions, with only parts of central Hubei experiencing intermittent haze [4]. - The Pearl River Delta region will have good atmospheric diffusion conditions with no significant haze weather expected [4]. - In the Southwest region, most areas will have good atmospheric diffusion conditions, with light haze in parts of the western and southern Sichuan Basin [5]. - The Northeast region will have good atmospheric diffusion conditions, with intermittent haze in the central part [6]. - In the Northwest region, most areas will have good atmospheric diffusion conditions, but the Tianshan northern slope cities will experience light to moderate haze. Dust or floating dust weather is expected from February 20 to 21 in parts of southern and eastern Xinjiang, western Gansu, central and western Inner Mongolia, Ningxia, and northern Shaanxi, with some areas experiencing sandstorms and severe sandstorms [7].