It could be representative of two young people, who're longing for each other's warm embrace but are unable to touch, as they have class separating them. And so, they are suffering in the storm, and waiting for the coldness to numb them, or smother them. Okay, that's sad.
It could be representative of a parent and a child, with the parent, showing the child how to brace the difficulties of the world. The child is awed by the fearsome blizzard that threatens, while the parent is trying it's best to shield the child from it. Okay, that's still sad.
It could represent a husband and wife, both having to share the burden of life. They try their best to cope, while the world around them continues to roil and inundate them with ever more problems. However, they know that they're never alone, and their partner is standing just beside them. Okay, still sad.
Eh, why are philosophical things so sad leh. Maybe it's just because, the picture is a sad one and can only be interpreted that way. Or maybe it's because the photographer saw the sadness, empathised with it, and decided to immortalise it in a picture.
Either way, if you can come up with any happy interpretations, please comment!
UPDATE: In case it wasn't clear. I'm the photographer. And it's not black+white!