What does blowing dust indicate in terms of visibility?

Blowing dust typically indicates that the dust particles in the air are being lifted by the wind, which can significantly affect visibility. When dust is raised and carried across an area, it can create conditions where visibility is reduced to less than 6 statute miles (SM), making it challenging to see objects clearly at a distance. This phenomenon is especially common in dry, arid environments where strong winds can easily disturb the ground and lift sediment into the air.

When evaluating the visibility in the context of blowing dust, it’s important to recognize that such conditions are usually associated with a noticeable degradation in visibility due to the concentration of airborne particles. The specific mention of less than 6SM highlights the extent to which visibility can be impacted.

In contrast, other options might refer to different phenomena or conditions not directly related to visibility restrictions caused by blowing dust. For example, while visibility below 3 nautical miles could also indicate reduced visibility, it does not specifically encompass the broader range associated with blowing dust. Dust storms in deserts may contribute to visibility issues, but they are a more extreme and specific phenomenon. Lastly, dust particles being present without visibility issues does not accurately reflect the usual impact of blowing dust on visibility.