Icicles in valleys

Hi folks...I have a contemporary colonial built in 2000. About 2700 sqaure feet. House is very well built with including several steel beams in the basement and one in the oversized garage. A builder built it for himself and overbuilt the house...no creaks or anything...just very solid and quiet house. My concern is the amount of icicles in the valleys after very heavy snow falls (we just had a 14 inch storm). The attic insulation is blown-in cellulose about 14 inches thick so about R-53 or so. I have full soffit and ridge vents. Attic is cold! I measure the temp of the sheathing which is at 32 degrees with an outside temp of 31 degrees (no sun though). I have zero bare spots on the roof when it snows but still seem to have some melting. All other houses in the neighborhood show the same symptoms so I'm thinking it's the weather. With the attic being so cold, why do I see so many icicles at the valleys during very heavy snowfall? Roof is in excellent shape and there are no signs of any leaks in the past. Attic has not been touched or altered since the house was built. Thanks for any feedback.

 

Are the icicles on the inside or outside of roof's valley?

 

They pretty much stay on the inside of the valley but I also have some along other parts of the roof. The attic is fully vented with baffles in each rafter...I can see day light. It's all been done correctly. One thing I'm wondering is with the style of the house. The attached garage is attached to the front of the house so there's limited venting at that portion of the roof. Then I have a bedroom with a cathedral ceiling that also has a roof peak opposite that of the main house creating two more valleys...same with the back of the house. I'm just wondering if that creates less venting. But the attic is cold...right at freezing. I don't mind the icicles so much as I'm sure there's ice/water shield on the roof and the roof pitch is at least 8 to 12 if not steeper. Just paranoid since I owned a previous house that had issues but that house was built in 77 and had poor insulation/ventilation etc.