Atmospheric Predictability
¥The atmosphere is like the ski slope with moguls!
¥The uncertainty in the initial conditions grow during the evolution of a weather forecast.
¥So a pinpoint forecast made for a long time in the future is worthless, no better than a guess!
¥There is a limited amount of predictability,   but only for a short period of time.
¥Loss of predictability is an attribute of nature. It is not an artifact of computer models.