I've given this a fair amount of thought: why is there a rune for ice, and a rune for hail (Hagalaz), but none for snow? Or for that matter, none for cold itself?
Perhaps because ice & hail are/can be destructive, whereas snow (unless you count avalanches) & cold aren't necessarily so? Snow & cold are normal; and unless extreme, rivers, (large) lakes & oceans are still navigable. Ice & hail cause real damage.
Yagh! Quotes within quotes don't render very clearly here, do they? I'll have to figure out how to fix that.
Anyway..
Snow can be quite destructive too though, for example, if enough weight gathers on a roof, the dwelling is done for; enough of it can also severely restrict mobility and gathering of food; or, as you said, in an avalanche -it could wipe out an entire village.
But also, interestingly, hail is referred to in all three poems as "cold grain", which has a positive connotation -when it melts, it turns to water. "Grain" being the key word here, as in seed, being that it waters the fields, or supplies the rivers and wells.
The more I think about it, the more I think Hail might be a catch-all term including snow too, but a linguist would know for sure.
But I tend to view Hagalaz as something that is a temporary burden or hurdle, but which can be turned to your advantage (it has a silver lining).
In the OERP hail is also the "sickness of serpents", a kenning alluding to the fact that winter is not kind to cold blooded creatures.
That also seems to be a good thing, and though some pagan cultures venerated the serpent, that bit was probably added later from Christian influences.