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Indef Ceiling Vis 700 AGL?

Old 10-01-2020, 09:00 PM
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Default Indef Ceiling Vis 700 AGL?

What does it mean when METAR is "Indefinite ceiling with vertical visibility of 700 feet AGL"?

More specifically, what weather phenomena or conditions cause this to happen?

Thanks!
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Old 10-01-2020, 09:40 PM
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Originally Posted by Lagoon View Post
What does it mean when METAR is "Indefinite ceiling with vertical visibility of 700 feet AGL"?

More specifically, what weather phenomena or conditions cause this to happen?

Thanks!
It simply means VV007. ‘Indefinite ceiling’ is part of the official definition of VV—there is no definite, defined ceiling...but your visibility in the vertical is 700ft.

When does VV come into play? Usually with fog. Fog is a cloud that touches the ground, so technically you’re in the cloud, so the ceiling can’t be above you, right? So instead of a ceiling, they say how far up you can see from the ground (vertical vis).

Curious...Where’d you get that from? Is it a decoded METAR?
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Old 10-01-2020, 11:49 PM
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Thanks for the explanation.

It’s a decoded METAR. I came across it one day and it was the first time I had seen that so I decoded it, but was still unable to visualize the conditions it could exist under. I was also not used to fog being coded that was. I always thought it was simply FG.

Now that you’ve posted it, I do recall seeing VV007 as part of the string.
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Old 10-02-2020, 08:24 AM
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What was the whole METAR? There’s going to be visibility report, the present weather and and the sky condition. So in your example maybe something like 1/8 SM FG VV007. So you can only see 1/8 of a mile horizontally and then looking up you can only see 700 feet. Fog is the most likely weather condition, I guess really heavy rain, smoke or dust could also lead to that type of report.
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Old 10-02-2020, 11:29 AM
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I only copied the part that I couldn’t understand, but I don’t remember anything else tacked on to the VV007, I think that’s why it threw me off. If I come across a similar example from my local airport, I’ll post it again. I always like learning more about METARS.
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Old 10-03-2020, 09:01 AM
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So before they redid the metars in 2004 the code would have been W007. That a W, not two V’s. That was decoded as indefinite. After 2004, they changed it to VV, or vertical visibility which means roughly the same thing; hard to tell, but this is what I think the ceiling is. I wonder if the code to English decoder in use in your example is combining the two or was in use prior to 2004 and was updated.
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