TonyR
A very good suggestion. Pilots seem reluctant to "join in" a pilot ATC conversation concerning weather, serviceability or the like with their own up to date observation. When it has happened I have always found it helpful for the pilot concerned and myself.
Why not give unprompted reports about pertinent factors such as a build up of TC / CBs you have spotted or the top altitude of a haze layer as is being discussed? It can only be to the benefit of other pilots and helps me build up a better picture of present conditions. Any information that helps a pilot make an informed decision about his flight must be good for safety.
I am of course talking from the point of view of area FIS and would not suggest this is tried on a busy control freq.
SWANFIS