I think the elephant in the room that no-one seems to care about is that with a less than 30% chance of FG it won't even rate a mention on a forecast.
Defred,
This is exactly what code grey was all about ie to cover this possibility. If I remember correctly it has to do with Australia slavishly adopting ICAO standards. Before they used to give " prob 10% fog" and the view was forecast fog is fog is fog whether it is 100% or 10% forecast...... Adjust your fuel carriage accordingly.