Global Weather
Obscuration Types
An obscuration is any phenomena in the atmosphere, other than precipitation, that reduces the horizontal visibility. The most common obscuration "seen" is usually fog. Obscurations include...
MistVisible minute water particles suspended in the atmosphere that reduces visibility to less than 7 miles (11 km) but greater than or equal to 5/8thmile (1 km). |
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FogVisible minute water particles (droplets) which are based at the Earth's surface and reduces horizontal visibility to less than 5/8th mile (1 km) and, unlike drizzle, it does not fall to the ground. |
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SmokeA suspension in the air of small particles produced by combustion. |
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Volcanic AshFine particles of rock powder that originate from a volcano and that may remain suspended in the atmosphere for long periods. |
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DustFine particles of earth or other matter raised or suspended in the air by the wind that may have occurred at or far away from the station which may restrict horizontal visibility. |
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SandSand particles raised by the wind to a height sufficient to reduce horizontal visibility. |
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HazeA suspension in the air of extremely small, dry particles invisible to the naked eye and sufficiently numerous to give the air an opalescent appearance. |
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