Dispatch by actual weather

[ranklein]

Hi all,

Looking to find a specific rule (ICAO, FAA) that enables using the phrase NOSIG in a METAR report as some sort of a forecast (2 hours one) for the destination.Can a METAR even serve as a forecast?

I believe a TAF would overule it if forecast weather is below what's shown and expected for the next two hours in the METAR.

Thanks!