Ohau

The northwesterly is intensifying and cooling on Sunday, bringing up to 40cm of new snow and gale northwesterly winds to the forecast area. Wind slab avalanches are likely, and bad weather will hamper safe route selection. Avoid travel in the mountains while the storm passes.

No new avalanches observed in the last 48 hours, but observations are limited by bad weather.

We have limited field observations from Saturday, but it looks like less precipitation arrived than forecast, with roughly 10cm of new snow above 2000m near the Divide, and trace amounts in the south of the forecast area.

Up to 40cm of new snow is expected at across the forecast area on Sunday, with the snow line falling to 500m through the day and gale northwesterly winds.

The old snow across the forecast area is generally well settled, with slick crusts on solar aspects and shady slopes below 2000m. Faceting has been observed in the lower pack, but after warm temperatures and lots of sun this should be limited to shady slopes above 2000m. We will be monitoring these layers as the storm brings additional load through the start of the week.

About the Main Divide: Heavy rain turning to showers with snow lowering to 500 metres, easing in the evening.

Wind at 1000 metres: Northwesterly severe gale 120 km/h, easing to westerly gale 80 km/h in the afternoon.

Wind at 2000 metres: Northwesterly severe gale 140 km/h, easing to severe westerly gale 100 km/h in the afternoon.

Freezing level: 2100 metres, lowering to 900 metres about the Mackenzie Basin.

Gale northwesterly winds will scour exposed areas back to slick crusts. Take an ice axe and crampons for travel at higher elevations.

Moderate

• We are confident the likelihood of avalanches will increase with the forecast weather.
• We are confident a natural avalanche cycle will begin shortly after the arrival of the incoming weather.
• We are uncertain due to a limited number of field observations.