Is the blue warning of blizzard accurate? Introduction of Blizzard Blue Warning

2. Blizzard blue warning signal is the first level (the lowest level) in blizzard warning. Usually, this alarm will be issued when the snowfall will reach more than 4 mm within 12 hours, or when the snowfall has reached more than 4 mm and the snowfall continues, which may have an impact on traffic or agriculture and animal husbandry.