Several people have sent this in: "Scots 'have 421 words' for snow", BBC News 9/23/2015:
Academics have officially logged 421 terms – including "snaw" (snow), "sneesl" (to begin to rain or snow) and "skelf" (a large snowflake).
The study by the University of Glasgow is part of a project to compile the first Historical Thesaurus of Scots, which is being published online.
The research team have also appealed for people to send in their own words.
Despite the source being BBC News, the article is only slightly misleading.
The Historical Thesaurus of Scots does exist, and is a laudable project with both scholarly and popular cred, and the cited words for aspects of frozen precipitation are really in it.
I was not able to find the "421 words for snow" in the online thesaurus — the link provided in the article leads to a search result with eight items, three of which are forms of "snaw", and offers further links to "Snow idioms" with six items, and "v(Snow/begin to snow)" with seven items, one of which is "snaw" again. There are some other snow-word subcategories indirectly available from the same page, like "Type of snow" (with two items), and "Snowball/action of thowing snowballs" (with four items, three of which are alternative spellings of snowball), but I didn't come near to 421 items (much less distinct "words") in a quick perusal of these links.
The 421-word total presumably came from Dr. Susan Rennie at the University of Glasgow, who is the P.I. of the team compiling the thesaurus, and who can presumably be relied on to provide a count with no more than a modest PR overlay. (Though I would not be shocked to learn from her that the article misconstrues something she told the reporter.)
But in any case, the usual Whorfian Words for X implication — that the Scots have subdivided the space of frozen-precipitation concepts especially finely, due to the pressures of their meteorological environment — is, as usual, not very well supported by the evidence provided. Excellent click bait, though.
For an earlier discussion of related issues, see Stan Carey, "Scottish Words for Snow", Sentence First 8/27/2013, which includes this picture of an art installation that features "31 words and phrases […] from a glossary of ‘conditions of snow and ice in Scots, Gaelic, and travellers’ cant’".
The BBC article also includes an obligatory gesture in the direction of the Eskimo snow-words meme:
It is often said that the Inuit have 50 different words for snow.
But at least it's reported as something that "is often said", rather than as a well-known fact.