Monday, 30 November 2009
A great day in Coire nan Lochan
Today Jack and I headed up to Coire nan Lochan to see what was in condition. We were looking for avalanche-safe mixed routes, grade II to IV. Unfortunately Jack was not feeling at his best, due to a bout of cold and generally not being on good form; he decided to turn back when we reached the coire floor.
It was an unbelievably good day, with perfectly clear skies, deep frost, and no winds at all: the sort of day every winter mountaineer dreams about, and every now and again we are blessed. I observed an avalanche cone at the foot of Forked Gully, and decided that all the gullies would probably not be a good plan in these conditions. Therefore I headed up Dorsal Arete, an uncomplicated but excellent Grade II which is often in condition and a safe bet when avalanches threaten other routes.
Dorsal Arete was in surprisingly good nick. Climbers yesterday had exposed some of the lower layers of snow and turf, which meant that the track up the ridge was frozen solid in many places, with hard turf and lovely neve. In other spots it was very powdery. I climbed swiftly, and when I topped out I decided that the day was so good I wanted to do another route!
Firstly I descended some nondescript mixed ground towards the face that contains the route Pearly Gates. I found the first pitch of this steep snow route to be in excellent condition, with frozen turf and solid snow. However, upon reaching the crux step I found the turf (much thicker here) to be poorly frozen, and the snow powdery, so I climbed back down.
I then climbed the large easy buttress to the left of Boomerang Gully. This route is not named, but provides a pleasant, avalanche-safe ridge route at around Grade I/II. On the way up, I investigated a section of Boomerang Arete, and found the turf to be only superficially frozen where it poked through the snow.
I topped out--for the second time!--to be greeted by one of the most spectacular sunsets I have ever seen in Glen Coe.
Conditions-wise, avalanche risk is still high in the gullies, with two separate layers of windslab separated by softer snow. This entire mass is resting on thawing grains (insulated from the cold by the snow above). Clearly, such a snow structure is unstable; I dug several test pits, which all failed dramatically.
Where turf was exposed to the open air, it tended to be frozen hard, but where insulated by snow it was generally unfrozen. There are dribbles of ice everywhere but they don't amount to much yet, except lower down in the coire, where the streams are beginning to form decent amounts of ice. The top third of the crags was well-rimed. The major ridgelines used by walkers are now consolidating well, thanks to a mixture of traffic, sun during the day, and deep cold at night; for this reason crampons should be carried by winter walkers on the high mountains, at least until the weather changes!
A thaw and re-freeze seems to be on its way, so let's hope that helps with consolidation. At the moment, the skies remain clear and it is -3 Celsius at glen level.
Photos from today