Term
|
Definition
The ceiling shall be the lowest layer aloft reported as broken or overcast. If the sky is totally obscured, the vertical visibility shall be the ceiling. |
|
|
Term
|
Definition
Height of cloud bases or obscurations for layer being evaluated. <=50 feet are considered a height of zero. If ceiling height increases or decreases rapidly, it shall be considered variable and the height is the average of the varying values.
|
|
|
Term
|
Definition
Ceiling Height Variation 1000 200 >1000 - 2000 400 >2000 - <3000 500 If variable and < 3000 ft, rmk giving range of variability. |
|
|
Term
|
Definition
|
|
Term
| Priority for Reporting Layers |
|
Definition
|
|
Term
Increments of Reportable Values of Sky Cover Height |
|
Definition
<= 5000 ft. to nearest 100 >5000 but <=10,000 to nearest 500 >10,000 to nearest 1000 If halfway between two reportable values, the lower shall be used. |
|
|
Term
|
Definition
If cloud is a TCU or a CB, append TCU or CB to cloud layer. e.g. TCUFEW050 |
|
|
Term
|
Definition
cumulonimbus cumulonimbus mammatus towernig cumulus altocumulus castellanus standing lenticular rotor clouds
|
|
|
Term
|
Definition
The sky cover shall be considered variable if it varies by one or more reportable values (FEW, SCT, BKN, or OVC) during the period it is being evaluated. |
|
|
Term
|
Definition
The amount of sky cover for each layer shall be the eighths (or oktas) of sky cover attributable to clouds or obscurations (i.e., smoke, haze, fog, etc.) in the layer being evaluated. |
|
|
Term
|
Definition
Clouds formed by the horizontal extension of swelling cumulus or cumulonimbus, that are attached to a parent cloud, shall be regarded as a separate layer only if their bases appear horizontal and at a different level from the parent cloud. Otherwise, the entire cloud system shall be regarded as a single layer at a height corresponding to the base of the parent cloud. |
|
|
