Greenefinger,
Have you ever heard people on these forums say buy a conifer with a single leader?
Well, that's why.
If they don't have a single leader, trunk, they can split like that in snow, sometimes they actually split and side branches fall off.
I don't know what to tell you to do.
I have one that has multiple leaders, but we dont' get snow here, so I am going to see if mine does that or not/
Post this on the conifer fourm, they will know what to do, short of digging them up, I hope you don't have to.
Are they in the front of your home?
Can people see that from the street?
Sorry about that. At least they wern't expensive.