常常见到有///的气象报文，有人问我遇到这种报文怎么办？

先说一下定义：

《中国民用航空行业标准民用航空气象第1部分》8.5.10：

在METAR和SPECI中，当天空状况不明但能提供垂直能见度的情报时，应按“VVnnn”的模式报告。当天空状况不明且没有垂直能见度的情报时，应使用“VV///”报告。

ICAO附件3：

4.5.4.4 Recommendation—In automated METAR and SPECI:
a) when the cloud type cannot be observed by the automatic observing system, the cloud type in each cloud group should be replaced by “///”;
b) when no clouds are detected by the automatic observing system, it should be indicated by using the abbreviation “NCD”; and
c) when cumulonimbus clouds or towering cumulus clouds are detected by the automatic observing system and the cloud amount and the height of cloud base cannot be observed, the cloud amount and the height of cloud base should be replaced by “//////”.

米国人的另一种说法来自咨询通告AC-0045：

Sky condition is coded in ascending order and ends at the first overcast layer.  At mountain stations, if the layer is below station level, the height of the layer will be coded as ///.

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说真的，我觉得///不能算作放行标准（个人想法）。因为很多情况下都是自动观测的结果，有必要的话，可以问一下气象台。我们不能因为///的出现而不放航班。

如果有不同意见，请告诉我。