What is the blue warning level of sandstorm? Is it serious?

1, blue warning: It is predicted that sandstorms with visibility less than 1000m will appear in most areas of two or more provinces (autonomous regions and municipalities) in the next 24 hours; Or has appeared and may continue, representing level 4.

2. Meteorological disaster warning signals are generally divided into four grades: blue, yellow, orange and red, which respectively represent general (grade IV), heavy (grade III), serious (grade II) and particularly serious (grade I). At the same time, it has been marked in Chinese and English, which is consistent with all emergency treatment levels and colors in the country. The blue forecast signal of sandstorm specifically indicates that sandstorm weather may occur within 24 hours (visibility is less than 1500m) or sandstorm weather has appeared and may continue. The yellow warning signal of sandstorm specifically means that sandstorm weather may occur within 12 hours (visibility is less than 1000 meters) or sandstorm weather has appeared and may continue. The orange warning signal of sandstorm refers to the possibility of strong sandstorm weather (visibility less than 500 meters) within 6 hours, or the strong sandstorm weather has appeared and may continue. The specific representative of sandstorm in red warning signal is that there may be extremely strong sandstorm weather within 6 hours (visibility less than 50 meters), or it has already appeared and may continue.