How crowded is busch gardens europe in williamsburg during howl-o-scream?

I'm trying to get my parents to take me to busch gardens williamsburg, VA, but I don't want to go If all the lines are 3 hours long. On a cloudy day, that is probably when we will go, if we do, how crowded would it be? I don't want to wait in line for 3 hours for griffon & 2-3 for alpingiest.