http://old.fai.org/civl-our-sport/safety/40754-assessment

Risks can be defined mathematically in a rather simple way, as the
likelihood of hazards multiplied by their consequences. To the question "Am I
going to hurt myself?", instead of "It should be OK, let's go!", this table is a
more structured answer. We are all different at assessing risks, some have a
strong preservation instinct, some are self-confident and like thrill. This tool
helps taking time, stepping back and watching calmly the situation. It
simplifies the hazard identification process of the SMS, making it easy to know
by heart and use in an instant, before or during a flight.

The green zone represents where flying looks reasonable, the conservative
approach. In the yellow zone, other factors should be assessed: personal worries
(divorce, unemployment), "currency" (first flight of season, new equipment),
pressure (short on time), fitness (tiredness), weather... One may enter this
zone, but staying aware that the odds are higher. The red zone gives access to
the statistics. "Is this flight worth my life, the catastrophe for my family,
the mourning of my friends and club, the bad impact on my sport?" The decision
should be just not to fly. Some examples: aerobatics cannot be green as an
adverse outcome is at least possible, cliff or towed launches cannot either as
the effects can be catastrophic.

More generally, being a weather expert is considered as normal for pilots. They
should have the same expertise in launch and landing skills, psychology and
safety knowledge, especially about the human factor. Meanwhile, let us remind
the traffic light: "Am I going to fly in the green zone, or in the yellow or red
one?" Let us enjoy the green!

http://old.fai.org/downloads/civl/assessment