Is the modifier correctly located in sentence approaching quickly from west front looked ominous?

No, the modifier "approaching quickly from the west front" is misplaced in the sentence. It's currently modifying "looked," but it should be modifying the subject, which is the thing that's approaching.

Here's the corrected sentence:

Something approaching quickly from the west front looked ominous.

This clarifies that the thing approaching is what looks ominous, not the act of looking.