Lochaber, including Ben Nevis, has a generally low avalanche risk

Climbers and walkers are being warned of the risk of avalanche in one of the Highlands’ most popular winter climbing areas.

The sportscotland Avalanche Information Service is reporting a high risk above 600m in the northern Cairngorms.

The high risk category means natural avalanches are likely even without human presence on slopes facing from north-west through to north-east – covering most of the popular climbing routes on Cairn Gorm’s northern corries.

There is also a considerable risk on western, eastern and south-eastern aspects, with moderate risk elsewhere.

The service’s observers report unstable windslab driven by strong southerly winds. The windslab is lying on a very weak layer of facets – sugar-like layers with very poor adhesion.

The SAIS reports say a weak snow pack is present on many aspects, with good route finding needed.

However, in Lochaber, which includes the Ben Nevis north face climbs, avalanche risk is low, with just localised areas above 800m where the risk rises to moderate.

Observers say there is ice on all the main gully routes on Nevis, and there is a dusting of snow to sea level, with good amounts above 700m.

The SAIS started its service last weekend in the two areas, almost three weeks earlier than planned, in the face of early large snowfalls.