Met Office: CH5 Cs increasing but below 45° elevation

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C_H5 Cs increasing but below 45° elevation

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Gallery
© C.S. Broomfield	© J.F.P. Galvin

Gallery

The main characteristic of C_H 5 is cirrostratus invading the sky progressively but with its continuous part still less than 45° above the horizon. There may be cirrus, frequently seen in bands, filaments, tufts, or resembling fish skeletons, ahead of the cirrostratus. The cirrus may have developed from C_H 4. (When such cirrus predominates over the cirrostratus at the same level, the coding in the C code is 0).

Cirrostratus near the horizon may be mistaken for altostratus, but the slowness with which it seems to move or change its appearance characterises cirrostratus. It is whitish throughout and differs from haze, which has a dirty yellowish to brownish colour.

Cirrostratus not completely covering the sky may be straight-edged and clear-cut as in the top photograph. However it is more common to see an irregular border as depicted in the bottom photograph.

Classification
Description: Cirrostratus progressively invading the sky and generally becoming denser, but the continuous veil does not reach 45° above the horizon.	Designation: C_H=5 (C2)
Latin name: Cirrostratus nebulosus (Cs neb) or Cirrostratus fibratus (Cs fib).

Classification

Description:
Cirrostratus progressively invading the sky and generally becoming denser, but the continuous veil does not reach 45° above the horizon.

Designation:
C_H=5 (C2)

Latin name:
Cirrostratus nebulosus (Cs neb) or Cirrostratus fibratus (Cs fib).