The Ill Wind modifier is being applied multiple times at the prison, once for each time you clicked use Location ability.
The first time you use the location ability, the difficulty is 11 (8 from the text and 3 from Ill Wind).
The second time the difficulty is 14, third 17, 4th 20, etc.
You can up the difficulty on a single attempt, by selecting the location ability, cancelling the ability, and reselecting the location ability.
The ramped up difficulty is also remembered through turns. (Turn 1 difficulty 11, end turn, turn 2 difficulty 14)