I took that picture because the terrace I was standing on has such a nice view of the Empire State Building, but it accidentally showed something else entirely.
Modern codes – including specifically ASCE 7, which is the source for wind loading in the NYC code and nearly all US codes – have a factor based on exposure to the wind. In simple terms, if your building is a condo on a beach, there is nothing to block any of the wind coming off the water; if your building is one story high and surrounded by forest, the wind will be partially blocked. Urban areas are considered to have obstructions as good as trees.
I was standing on a terrace on the 32nd floor when I took that picture, looking east and south across midtown south. There are any number of low-rise (mostly 4- and 5-story buildings) in the path of my view, but you can’t see them. What you see is the vast collection of 15- to 25-story mid-rise buildings that form the background for much of Manhattan. It gets windy at street level in Manhattan, but there are a lot of buildings blocking free passage of wind for the first 100 feet above grade.
