In the novella, there is no wind, not even a light breeze when they are in Bangor. Since this was virtually impossible to execute for the movie they simply created dialogue to explain that even with a wind down here the clouds are not moving.
In a scene, one of the characters mentions it's impossible to go back in time, and for example stop the Kennedy assassination. This is the main topic for one of Stephen King's more recent novels, "11.22.63"
When Dean Stockwell's character says that it is not possible to travel through time, he mentions stopping the Kennedy assassination. In Quantum Leap (1989), Dean Stockwell's character helped Sam (Scott Bakula) try to stop the Kennedy assassination through time travel.
The trivia items below may give away important plot points.
What Nick is apologizing to his father for, the incident behind the church in Belfast, was the death of some boys. The children were chucking what looked like hand grenades and Nick gunned them down immediately. He would later find out they were painted potatoes and not grenades.
While Dinah is lying mortally wounded in the jet, communicating with Toomey through his hallucinations and trying to get him to get up and go outside to join the imaginary board meeting, she says, "Yes. I will if you want me to be." In the novella, this is in response to Toomey saying to her, "Are you an angel of the morning? Will you be my angel of the morning?"