Heavendrift...

It's another snowy day in Edinburgh.

Several inches of frosted snow cover the ground, with the bright, crystaline solidity of a thick layer of icing sugar. The air is bracingly cold, and the open sky is a perfect, cloudless blue. Beneath the blankets of snow, there is an impressive hardness, a geological pattern of stone and wood and icy water.

Every day seems different, though. Today, we have clear skies and there's a wintry stillness to the settled snow; tomorrow, a hint of pink cloud suggests we may be in for a blizzard; and that's just the start of it - sending me searching for words to describe this marvelous weather. Sitting with a big dictionary and a warm fire, I've been exploring the language of snow, something that we seem to have almost lost in recent decades.

Over the weekend, we had big, soft snowflakes - or flichts or flocks, as they're called in Scots, catching the etymological connection with flight that's been rather lost in standard English. You know the type - the light, feathery, fragile-seeming kind, which ride slowly from the sky like eiderdown.

There's also flindrikin snow, which is thin and light and fluttery - either like butterfly wings or white lace, the dictionary isn't sure; but either way, the word seems very appropriate.

First, though, there was a type of snow that the weather professionals refer to by the German name graupel, a name which seems to mean "barley-like". This is created when snow passes through moisture in the air, and the water vapour freezes around each snowflake, turning them into fragile pellets - hence the rather misleading name of "soft hail".

But it's not really satisfying to use a loan-word auf Deutsch or the underwhelming "soft hail", and there's no evidence of an English nauralization like "grapple". So what do we call this?!

There's one dictionary reference to "bullets" as a Scots term for "frozen snow" in 1914, but the nearest word in regular use is "moor", which describes a heavy fall of powdery snow. The graupel was certainly "mooring", to use the verbal form that seems rather more common than the noun - coming heavy and fast, in drifts through the sky.

I went for a walk in a blizzard a few days ago, and detoured into the Botanic Gardens. The cafes were shut, but the art gallery in Inverleith House was open, and the paths had been cleared with a little snow-plough - seemingly the only one in Edinburgh that actually works. And as I walked, I watched the snow come mooring through the trees in a tumbling whirl, to add to the deep snow already fast on the ground.

But "moor" isn't quite mainstream Scots - it belongs to the Viking dialect of the Northern Isles, which sit at the intersection of Atlantic and North Sea weather systems. I've seen driving snowstorms and shirt-sleeve summer sunshine alternate in five-minute intervals on Orkney, so this is probably a good place for the unusual combination of cloud levels that produces graupel.

In Edinburgh, however, I suspect the cause was the vapour trails from planes at the airport. It certainly disappeared when the snow shut down the runways. So "moor" doesn't seem quite appropriate for this post-modern snow.

But while I'm still looking for a better word than graupel, Scots has another word for the dramatic way this snow was falling: "yowdendrift".

In contrast to an "erdrift", an 'earth-drift' or normal snowdrift, a "yowdendrift" is a heavy, blown fall of snow that's swept down out of the sky like a snowdrift from on high. This is another word that confuses the specialists, with the Scots National Dictionary suggesting it derives from our language's equivalent of 'yielded', which doesn't make much sense.

I prefer an alternative kenning of my own, based on the earliest recorded form, ewindrift (c. 1650), the only citation before the last years of the eighteenth century; this looks like 'heaven-drift' (Older Scots "hewin"), and as such, it seems to fit in a pair with "erdrift", gives an accurate sense of how the snow comes billowing in from on high... and is quite simply a rather lovely word.