noun
break in the weather; weather turning bad
Refers to a change for the worse in weather conditions, often used in forecasts or when describing a sudden deterioration.
明日は天気の崩れが予想されます。
A break in the weather is expected tomorrow.
午後から天気の崩れるおそれがあります。
There is a risk of the weather turning bad from the afternoon.
悪天候 is a more formal term for 'bad weather', whereas 天気の崩れ emphasizes the process of the weather deteriorating.
Compound of 天気 (weather) + の (possessive particle) + 崩れ (noun form of 崩れる, 'to collapse, break down'). Literally 'collapse of the weather'.