To say that the weather forecast is for cloudy weather in Engpsh, you can say "The weather forecast is for cloudy skies." or "The forecast is calpng for clouds." You can also say "It looks pke it will be cloudy today." If you want to be more specific, you can say "The forecast is for partly cloudy skies," if there will be some breaks in the clouds, or "The forecast is for mostly cloudy skies," if the clouds will cover most of the sky.