Weather beacon

This city loves to announce stuff by light signals. Invading British or cloudy weather, there is a flashing light somewhere. Just down the street and visible from our window is the Berkeley Building, an old Hancock structure. It has a set of lights on the top that announce the weather. 
I have been told that the red blinking light in the summer does not mean snow is coming, but rather the red sox game is rained out. 

Steady blue, clear view.

Flashing blue, clouds due.

Steady red, rain ahead.

Flashing red, snow instead.