Always coded as VCFG regardless of visibility in the obstruction, and without qualification as to intensity or type (frozen or liquid). *The VC group, if used, should be the last entry in any significant weather group.

The initial time period and any subsequent FM groups include a cloud or obscuration group (N N N h h h or VVh h h or SKC), used as appropriate to indicate the cumulative amount (N N N ) of all cloud layers in ascending order and height (h h h ), to indicate vertical visibility (VVh h h ) into a surface-based obstructing medium, or to indicate a clear sky (SKC). All cloud layers and obscurations are considered opaque.

The cloud group (N N N h h h ) is used to forecast cloud amount as indicated in Table 27-6.

When 0 oktas of sky coverage are forecasted, the cloud group is replaced by SKC. The contraction CLR, which is used in the METAR code, is not used in TAFs. TAFs for sites with an ASOS or AWOS contain the cloud amount and/or obscurations, which the forecaster expects, not what is expected to be reported by an ASOS/AWOS.

Heights of clouds (h h h ) are forecast in hundreds of feet AGL.

The lowest level at which the cumulative cloud cover equals 5/8 or more of the celestial dome is understood to be the forecast ceiling. For example, VV008, BKN008, or OVC008 all indicate an 800-ft ceiling.

The vertical obscuration group (VVh h h ) is used to forecast, in hundreds of feet AGL, the vertical visibility (VV) into a surface-based total obscuration. VVh h h is this ceiling at the height indicated in the forecast. TAFs do not include forecasts of partial obscurations (i.e., FEW000, SCT000, or BKN000).

Example:

Ceiling is 800 ft due to vertical visibility into fog.

The only cloud type included in the TAF is CB. CB follows cloud or obscuration height (h h h ) without a space whenever thunderstorms are included in the significant weather group (w’w’), even if thunderstorms are only forecast in the vicinity (VCTS). CB can be included in the cloud group (N N N h h h ) or the vertical obscuration group (VVh h h ) without mentioning a thunderstorm in the significant weather group (w’w’). Therefore, situations may occur where nearly identical N N N h h h or VVh h h appear in consecutive time periods, with the only change being the addition or elimination of CB in the forecast cloud type.

Examples:

Thunderstorms are forecast at the airport.