I'm not sure I understood the exercise! Maybe I'm still... sleeping, this morning. :)
I think you are talking about a peculiar kind of "suffixes": the ones concerning the so called "alterations".
We have four kind of these suffixes: diminutive, augmentative, pejorative and "vezzeggiativo", that is translated as "term of endearment".
The main of these suffixes are (on male singular form):
term of endearment: -uccio
So, in your exercise you could use:
vent-accio (pejorative of "vento", meaning a strong, bad kind of wind)
nebb-ione (augmentative of "nebbia", a very thick and impenetrable fog)