Your reference to volcanic ash reminded me of the article I sent to the doves’ site this year, asking about volcanoes in the clouds; from a previous dream. These two dreams (’volcanic clouds’ & ‘snow’) could be related. The other question is whether I’m very certain whether the location fits only Crete-Greece region? The answer is NO. Reason: because in the dream I thought it was around Scandinavia. But after checking on the map Crete-Greece region appealed to me.
 
Conclusion, if it’s some phenomenon that’s coming it’s safe to keep watching both the regions around Scandinavia and Crete-Greece. However, it could be just strange dreams.

God bless you.

Simon.