UKC

I was thinking of shooting up to Fort William for a few days - climbing Thursday to Saturday and maybe Sunday. However temperature forecast doesn't look great. Metoffice says max of 4 degrees Thursday and 6 degrees Friday and Saturday for Fort William. That may be alright for routes on the Ben but MWIS says temperature at 900m on Thursday will be 4 degrees, which suggests there will hardly be any lapse rate (I guess due to humid air coming in from Atlantic).

Metoffice says it will go down to around 2 or 3 degrees overnight in Fort William, so is it fair to assume that should cause enough of a freeze higher up for routes to be in condition during the day? yr.no is forecasting -5 to -6 every night (except Saturday night) for the summit of the Ben.

I'll be going from south England so not sure whether it's worth the gamble...

In reply to Julian Prieto:

The routes high on the Ben will be totally fine this weekend. Go for it! Loads in condition.

In reply to Kevin Avery:

Thanks Kevin. So am I being too paranoid? MWIS forecast of freezing levels above summits worries me...

In reply to Julian Prieto:

Sounds like there may be a wee bit of a temperature inversion going on. Nothing severe though and the high North facing corries shouldn't be too affected. There is some great ice about up there at the moment by all accounts.

In reply to Kevin Avery:
I have found inversions where the climbing is much above 3 degrees the ice is melting and dripping. If there is clag on the crag (ie it's humid) it will be melting at anything above 0. How much of an issue this is depends on how much you are relying on ice screws and how much above these temperatures it is.

In reply to Julian Prieto:
Aonoch Mor gondola staff reporting an inversion today, -6 in carpark 0 on summit. We're climbing there tomorrow and on Ben Nevis Thursday and Friday so can report back if you like although guess you'll have made a decision by then?

cheers from sunny Glencoe

In reply to Julian Prieto:
Some of the best days I've ever had on the ben were in clear skies with the summit temps of 2-3 degrees. But that was in clear sunny high pressure, quite a different story if clagy.

In reply to Oli_31:
currently 2.3 on the top of aonach mor,
http://www.weatheronline.co.uk/weather/maps/city?LANG=en&SI=mph&CEL...

and sunny on the ben
http://www.visit-fortwilliam.co.uk/the-ben-nevis-webcam-fort-william-scotla...

Bet it was a great day to be on the hill!

In reply to Oli_31:

We need to decide tonight or tomorrow morning whether to go, but thanks anyway! It would be interesting to know what conditions were like today if there was an inversion.

In reply to Julian Prieto:
I'd be very surprised if they weren't excellent today I've been out on many days like today and had a great days winter climbing. Summit of Aonach Mor stayed under 2.3 C all day.

In reply to Julian Prieto:
Tomorrow 5c at 900 could be quite a different story depending at what level the inversion is at (assuming there is one) / lapse rate is.
http://www.mwis.org.uk/jtvancxobeqzcjw/WH.PDF

In reply to CurlyStevo:

I was climbing on Aonach Beag last week and the temperature was plus 6. The snow stayed fully frozen and conditions were great.

In reply to Andy Nisbet:
fair enough perhaps the air was still enough to cause a freezer effect in the north(ish) faces, coupled with the wet bulb / high pressure effect kept everything good.

Tomorrow does look OK on MWIS right enough, Thursday / Friday much will depend if you are in hill fog or not I guess.

In reply to CurlyStevo: Theyre just forecasts....

In reply to Ecosse Mountains:
true enough, however I find gambling on the forecast is more attractive the closer to your destination you live!