It ain't snow - it's ice, that's the problem.

I have forty feet of maple tree fallen in my front yard, and half of a fifty foot tall pecan tree down out back from the weight of the accumulated ice that stuck to them. The jury is still out on what the weather will do here, and hopefully it will begin to warm and melt all that stuff off, but Murphy tells me not to expect it.

Add to that - if it warms during the day and then re-freezes the water can get into cracks in wood and in freezing again cause more splitting at the micro-level. This weakens the wood considerably and is progressive.

That effect right there is why you never ever want a leaking roof on an RV - because it can tear up a whole trailer, 5-er, or motor coach so fast it isn't even funny.

Homes tend to be less vulnerable because they have asphalt roof shingles and usually a barrier layer underneath. But when water seapage gets into wood in the winter it can swiss cheese things in a heartbeat or an eyeblink!

Think of it as a million tiny jackhammers tearing up the wood fibers from the inside...

Water is not compressable, but when it turns to ice it expands as we know.

When wood is saturated by water and the water then freezes - it forces the fibers of the wood apart. This tends to open up any cracks or pores of the wood, and when the ice turns back into water it seeps in deeper. If it freezes again - it opens the gaps even further - which is very much like driving a wedge deeper and deeper into a split.

This is why I said above that it is a 'progressive' effect.

Add to this (as if it doesn't sound bad enough) WOOD is a natural insulator - it tends to protect itself from temperature change. But water or ice transmit heat almost instantaniously - think of what happens when you run cold water on a hot pan from the stove. Chills it pretty quick, doesn't it?

So, if water intrudes inside of a tree trunk or limb - it also causes the interior of the wood to chill faster, and so the process increases in speed.
~ The deeper it goes, the worse it gets