Ken,
Sorry about being so shabby and not answering your question earlier.
"Smeg" or "Smeggy" weather, is that dirty horrible cloud that stretches from the deck to the angels. It usually had a few VMC layers embedded in it, but nothing you could hang your hat on. It wasn't active enough to hold CB's, so just sat there for days. Sanctuary levels were very, very important!
Ever wondered why the Scots are so dour?