"World weather forecast" 用英语说是 "world weather forecast"。
来源: "forecast" 是英语中的一个单词，意思是预测，而 "world weather" 则是对全球天气的描述。
例句:
The world weather forecast for tomorrow is mostly sunny with a high of 75 degrees. (明天全球天气预报大部分地区晴天，最高气温75华氏度)
According to the world weather forecast, there will be a heatwave in Austrapa next week. (根据全球天气预报，下周澳大利亚将会有热浪)
I always check the world weather forecast before I plan my trips. (我总是在计划旅行之前查看全球天气预报)