Schön wetter pilot

Or perhaps schönes wetter pilot, or schöner wetter pilot...f if I know the grammatics. The point is that this is an expression I learned today. In English it means "nice-weather-pilot". And I believe it means something like a person who is good in good times, but not in bad. Or when he/she feels good, everything is great. When he/she doesn't everybody else has to go with it.

I just happen to know a few people like that...