Lochaber Blog & Mountain Info » It’s all about aspect

It’s all about aspect

20th March 2025

Slope aspect (the direction that a slope faces) is frequently mentioned in the avalanche forecast when describing where the avalanche hazard is. Most commonly the aspect that the hazard is on depends on the recent wind directions with lee slopes being the location where windslab accumulates.

Currently however it is how much sun that an aspect gets and the prevailing wind directions through the winter that are the more important factors. The prevailing wind direction has been South-Westerly which currently gives the deepest deposits of old snow on North to East aspects. The last snowfall came with light winds and gave a layer of soft snow on all aspects. The sun has melted nearly all of this snow on East through South to West aspects but some remains on high, steep, shady North-West to North-East aspects where it still looks quite wintery.

The photos below show the differences between opposite ends of Coire an Lochan and Coire Dubh on Aonach Mor where there is a relatively small change in aspect. If you compare the photos of The North faces of Aonach Beag and Ben Nevis below with the photos of the South sides of these mountains that were in yesterdays blog you will see a much bigger difference.

The more wintery South side of Coire an Lochan which has a North-East aspect.

There is a lot of dry rock at the North end of Coire an Lochan. These crags face East-South-East and get a lot of sun.

Coire Dubh. Noticabely less thawing at the far end of the corrie which faces North-East, than the near end which faces East.

Looking Down Easy Gully. This would have given a good ski today with spring snow and would have given the longest available run on Aonach Mor.

A large glide crack in Coire an Lochan. This is common in spring time below the crags here but in this case isn’t a signal of an avalanche hazard.

A few cornices are still present.

The wintery North face of Aonach Beag.

It still looks wintery high on the North face of Ben Nevis although there’s a lot less snow here this year than there would normally be at this time of year.