Tiānqì yùbào yòu cuò le!

天气预报又错了！

The weather forecast was wrong again!

Notes:

天气预报(tiānqì yùbào): weather forcast

又(yòu): again

错了(cuò le): be wrong

Example:

A：下雨了！

    Xiàyǔ le！

    It's raining now.

B：天气预报又错了！

     Tiānqì yùbào yòu cuò le! 

    The weather forecast was wrong again!