Analyzing Word Choice for Foreboding Sense

Read the following excerpt from a fictional narrative:

"As the storm raged outside, Emily sat in her dimly lit room, cocooned in a rhythm of anxiety and anticipation. Each roar of thunder felt like a reminder of the chaos beyond her walls, a visceral echo of her own trepidations. She hugged her knees closer, the fabric of her sweater scratching against her skin, as the winds howled like wailing banshees, urging her to confront the tempest both outside and within."

Which word in the passage most significantly contributes to the sense of foreboding that permeates the narrative?