后天英语天气预报怎么说

To describe the weather forecast for the day after tomorrow in English, you could say "The weather forecast for the day after tomorrow is..." and then provide the forecast, such as "sunny," "partly cloudy," "rainy," etc. Here are a few examples of how you might complete the sentence:

The weather forecast for the day after tomorrow is sunny with a high of 75 degrees.
The weather forecast for the day after tomorrow is partly cloudy with a chance of showers in the afternoon.
The weather forecast for the day after tomorrow is mostly cloudy with a slight chance of rain.

It's also possible to use more specific language to describe the forecast, such as "temperatures will be in the mid-70s" or "expect scattered showers throughout the day." You can use a variety of words and phrases to provide a detailed forecast for the day after tomorrow.