When you say that something is `noticeable’, what you mean is that it is apparent. In other words, it is obvious; it can be seen or `noticed’ by others.
Examples: There is a noticeable improvement in the champion’s backhand. *What is noticeable is that the two brothers just can’t stand each other.
Anything or anyone that is important or interesting is `notable’. The word is normally used with people who are well known. It can also be used to refer to their impressive accomplishments.
Example: Winning the Grand Slam twice is one of his notable achievements.
`Notables’ is normally used to refer to important or powerful people.
*Many of the local notables decided to stay away from the event.