晴天 せいてん らん気流 きりゅうではありませんでした
seitenrankiryūdewārimasendeshita

Noun
Desu Copula

The polite, past negative form of 晴天乱気流

1. It was not clear skies and turbulence.; It wasn't clear skies with turbulence.

Past/Perfective
Negative
Polite
Formal Register