Snow builds up on a roof and starts to melt because the warmth of the attic. As the water runs down it gets to the overhang where there is no warm surface and turns to ice. The more the water runs down and freezes, the more the melting water builds up, and backs up, on the roof. The water eventually gets under the shingles an runs down the trusses and can end up inside your walls or soffit.
The water, seeking the least path of resistance, in your case, is running behind the siding and as it gets to the weap holes, freeze.
This should be at the top of the wall.
Now if the freezing is lower on the wall, you have to see just how far down the water is coming out.
If it's coming out between the area of the first and second floor or any part above it, it could still be an ice dam that has traveled down the inside of the second floor wall and is getting out when the water hits an obstruction.
If the water is coming out below where the second story begins, it should be below the top J channel of the first floor windows, you may have a window(s) that are not flashed properly. (this may happen on the second floor as well. but, it should have the same pattern on both floors.)
If you remove the ice at the edge of the roof your problems may go away.