A few Scottish words:
Feefle: swirling snow
Spitters: small drops of wet snow
Skelf: a large snowflake
Dreich: really nasty, gloomy, dismal, wet weather.
Example: "We were so looking forward to our vacation, but the weather was such gray dreich, we never left the house."
And an English word, from Kent:
Aquabob: an icicle