Mal Grey wrote:I was once out on the Drumochter hill on a day when the Cairngorm Weather station recorded a gust of 150mph...there were times that day when we couldn't crawl, and one moment when whilst lying down I couldn't bend my leg to reach my foot to tighten a loose crampon strap. In retrospect, it was silly being up there, but it was a very rounded bit of hill, close to the road, and it was actually great fun!
Similarly I once had a day on Ben Chonzie from the Lednock side (14 March 2009) when even crawling wasn't feasible at times. Got to the top OK, staying upright even though it was already very windy. Then had a bite to eat at the cairn during which time the windspeed increased significantly, plus the return leg (heading SW) was into the teeth of it. The first couple of hundred horizontal metres took 20 minutes and included lengthy spells of being just stuck. Was slushy underfoot/underknee so not very pleasant. Eventually managed to crawl/scuttle round to the left in a few lulls and then use the slope to give a bit of shelter and allow progress. Checked the weather reports when I got down and there'd been a gust of around 125mph at Glen Ogle, which fits with what Mal says re his own experience. It was certainly memorable, and just about still fun in its way, but my main thought was that had I been 300m higher, on the Cairngorm plateau with ice rather than slush and some proper cliffs around, then I might well not have survived it.
Big dome-like hills often seem to catch the biggest winds - Chonzie and Drumochter fit the bill, and the second-windiest outing I've had was on Skiddaw from the north - oddly exactly the same height, 931m, as Chonzie and a similar type of hill with not much in the way of corries to break up the wind which then just screams over the summit slopes unhindered. There's not really anywhere to hide on hills like that in those kind of conditions.
I've had four or five other crawling days over the years, and plenty of others when I've substantially changed the route to get the wind behind me particularly in descent. Hard to put precise figures on it but I tend to think that up to 60-70mph you should be able to stay on your feet although probably not progress in a straight line, and moments when you have to brace yourself against the gusts will come into play. Maybe 80-90mph it's a crawling job, and above 100 even crawling is going to be problematic as per my Chonzie and Mal's Drumochter days.
