Today Nick and I went to climb North East Buttress on Ben Nevis. A hard frost in the glens was reversed higher up as we experienced warmer air from a temperature inversion near the CIC hut. We were shaded under the north face but there was blue sky above and we even caught a little sun as we traversed to the first platform. At least 2 parties have done the route in the last couple of days and the snow has settled and refrozen in places. This meant we followed footprints rather than having to clear everything ourselves. We had some refrozen snow and turf solid enough to take a good swing of the pick but also a lot of fresh thin glassy ice choking cracks from thaw and refreezeing. As we tackled the mantrap high on the route a Royal Naval Sea King helicopter circled the top of the mountain. Later when we topped out we could see where a flare had been used on the summit so I don't know if it was picking someone up or even part of a rescue. On our descent we passed a couple of guys who had had a good traverse of the Carn Mor Dearg Arete and we found ourselves in the wind we had been sheltered from all day. This wind had deposited impressive drifts of snow on the zizags of the bridle track- several feet deep and blocking half the width of the path. So less snow but more consolidation. Plenty of bare rock but also verglas in cracks.