Phenomenal phenomenon

As a foreigner using English as a second language, I am always curious about any questions related to this language. An interesting discovery gradually floated its way out of my mind since last week of my first combat with the word “phenomenal.”

Last Tuesday, I was struggling on my kayaking rolls in a pool. After tons of unsuccessful attempts, my helper Larry who looked as frustrated as I was, suggested to me that he was going to grab this kid from the other side of the pool to coach me, since “he has this phenomenal roll.”

I wondered, “Phenomenal, isn’t it the adjective of phenomenon?” As a science major, to me, “phenomenon” just means something people observe, something noticeable that we have to call it phenomenon. However, something noticeable does not necessarily imply excellence or extraordinary, therefore the word “phenomenal” must only carry neutral senses. I was puzzled; my little wish was to do the rolls in a standard way, and I definitely do not want to draw any attention. Do I really have to do this phenomenal roll?

Forgive my little knowledge about English. After I went home, I looked it up in the dictionary: A sense of phenomenal says “extraordinary; outstanding; remarkable.” When notice becomes noticeable, noticeable does not imply good or bad. But how come something noteworthy has to be good stuff? Don’t people think the absolute evil is noteworthy?

I also found some similar pairs of nouns and adjectives, which seem to share the same nature: the adjective derived from the noun describes a good state. They are:

Phenomenon; phenomenal
Impression; impressive
Remark; remarkable

But I could not find a pair that goes to the exactly opposite direction. The only pair I found after an extensive search was: (obtrusiveness; obtrusive). What else?