If the sky cannot be seen because of a smoke layer that hides 8/8 of the sky, what is the sky cover contraction used?

When evaluating sky cover reports, the contraction used indicates the amount of the sky that is obscured or covered by a particular condition. If the sky cannot be seen due to a smoke layer that obscures the view entirely, the relevant term would correctly reflect that the sky is completely hidden.

The contraction used for complete obscuration of the sky by factors such as smoke, fog, or other atmospheric phenomena is "VV," which stands for "vertical visibility." This indicates that the observer cannot see the sky at all due to the presence of the smoke layer.

Other options correspond to different levels of sky cover: "SKC" indicates that the sky is clear, "FEW" is used for a few clouds present, and "OVC" indicates that the sky is overcast with clouds, but in this instance, the smoke prevents any visibility of the sky. Hence, "VV" accurately captures the situation where 8/8 of the sky is obscured and visibility is effectively zero.