Training Guide in Surface Weather Observations - Multiple Choices

After determining the sky cover and sky cover contraction for each layer aloft, enter the contractions in
column 10, Sky Condition, of MF1M-10 in ascending order of height, and enter the sky cover of the
highest layer in column 17, Total Sky Cover. If the contraction for the highest layer is OVC, the entry
in column 17 must be 8 (for 8/8 sky cover). If the contraction for the highest layer is SCT, the entry in
column 17 must be either 3 or 4. If the sky is clear (meaning no cloud or obscurations), the entry would
1
be SKC in column 10 and 0 in column 17.
Examples 5-7 through 5-12 show how the illustrated sky condition is recorded in column 10 of MF1M-
10. In each of the illustrations, note how the sky cover was determined and how the contraction was
selected. The sky cover contraction precedes the layer height with no space. Cloud and ceiling height
are discussed in the next section.
1
If less than 1/8 of the sky is covered by clouds or obscurations, a zero would still be entered in
column 17; however, FEW would be used as the contraction.
2
3
4
SC - Stratocumulus
AC - Altocumulus
CI - Cirrus
2 3 4
Example 5-7. Three Multiple Layers
5-13