/ Snowdonia Avalanche forecasting

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Trevers - on 18 Mar 2013
Planning to head to North Wales for a long weekend. I'm pretty excited but also a bit worried by the accumulations of snow, which look considerable from the webcams. Is there a service that provides avalanche forecasting for Snowdonia similar to the SAIS in Scotland?
Banned User 77 - on 18 Mar 2013
In reply to Trevers: no
Webster - on 22 Mar 2013
In reply to Trevers: been up there the last 3 days and coverd allot of ground and aspects. In general despite the large build up avalanch risk appeared minimal due to the fact that despite several days of intermittent snowfall, there has been no consolidation inbetween falls, so no layers/slabs have formed and the snow is resting on the bare rough rocky surface of the underlying ground which prevents major fails. there are some large unstable looking cornices around which are best avoided, but other than that i think you should be ok (note as always conditions are changable day to day so vigilance is still required)
CurlyStevo - on 22 Mar 2013
In reply to Webster:
Did all the gullys melt right back before the last snow fall? I think a significant number of the avalanches involving humans being caught up in them in the UK involve gullies (or steep pronounced corries which have similarities) and it's not uncommon for them to be human triggered. Also its worth bearing in mind that if a cornice does collapse or partially collapse its likely the slope below will avalanche.

IMO wind slab especially fresh wind slab, is in general suspect especially as it builds up depth (and / or as you say rests on an icey surface). Part of the problem is you don't know what that wind slab is resting on, is a layer of depth hoar crystals formed where it meets the ground, is it on smooth grass or rock slab, is there some old neve there? etc
rusty8850 - on 22 Mar 2013
In reply to Trevers: Given the very high winds and driving snow we experienced in Bethesda last night I would think an avalanche hazard on some aspects would be highly likely. Take care.
Johntherock - on 22 Mar 2013
It's not particularly cold either, but very windy. Sleeting at valley level here (Machynlleth) but snow level only about 200m. Even higher up the snow could be quite wet in nature and dense, forming large and potentially unstable cornices along N/NW aspects.
Rob Johnson - on 22 Mar 2013
There is a lot of wind blown snow forming as windslab on leeward slopes and being cross loaded in gullies. There will definitely be a high avalanche risk this weekend in Snowdonia.
Mark Handford - on 22 Mar 2013
In reply to Trevers:

Avalanche Hazard Considerable - Natural avalanches highly likely, human triggered avalanches possible.
Wind slab on slope aspects from NNW through to NE with local eddying in the Cwms leading to cross loading as the winds change direction over Sunday to Monday transporting snow.
Also be aware that although the slope angle is generally 30 to 33 degrees, in locations with Maritime snow conditions, ie Wet Snow, the steeper angled slopes do not slough off as they do with dry snow, so anything up to 55ish degrees has the ability to have a cohesive snow pack and be an avalanche hazard.

Dont go in gullies, dont go on slopes in that avalanche angle, ridges safer except for the high winds!

Stay at home folks and wait a few days for the snow pack to settle or just go sledging Leave it till next week.
georgebe - on 22 Mar 2013
The forecast is looking better for Sunday but do people think there will have been time for the conditions to settle by then?
Will Nicholls - on 22 Mar 2013
In reply to Trevers: I went into Cwm Glas Bach yesterday afternoon, there was debris at the bottom of Parsley Fern Gully. I found 5 layers in the snowpack with a harder/icier layer third down and a deeper top layer of windslab forming. We decided against our plan and walked off. A friend in the same area today set off a small slide, as he'd expected. Be careful!
marmot hunter on 22 Mar 2013 -
In reply to Will Nicholls:
Perfect Avalanche conditions! no doubt people will go out regardless of the advice.

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