Question

What is the meaning of the phrase "the clouds that lour'd upon our house"?

Answer 1

It is a metaphor for troubles and hard times. He says that these "clouds" are now gone, and this is due to the fact that "the winter of his discontent" is over, due to the joyous reign of king Edward IV. 

Answer 2

This phrase is from Shakespeare's Richard III in the opening of the play. The first four lines with the given one is:

Now is the winter of our discontent

Made glorious summer by this son of York,

And all the clouds that loured upon our house

In the deep bosom of the ocean buried.

The meaning is that all the troubles of the family have ended and thanks to, King Edward IV. All the clouds that threatened the York family have vanished away.