In reply to newtonmore:
I would have expected the its to be scoured clear and bone dry in these westerly winds and cold temps!
To the OP, don't know about recent conditions on the crag itself, however the Cairngorms have been fairly dry this winter so I would expect seepage down the lines to be less than normal and with this wind very little lying snow on the face to run down if there's any freeze thaw. If it says cold thing may well form especially if we get a few cycles, but I'd be tempted to wait a good few days yet!