Moderate to strong southwest winds may shift the new snow and continue to build a wind slab hazard during the day.
Careful snowpack evaluation, cautious route-finding and conservative decision-making are essential
Storm and wind slab formed over the past few days may exist on a range of aspects and may still be touchy. If strong southwest winds persist, we may see an ongoing buildup of wind slab during the day, particularly above 2000m, where colder, larger quantities of snow fell from the last storm.
Be conservative with your plans on Saturday and give the new snow and wind loading another day to settle.
No recent reports, although a cycle of natural wind slab avalanches has likely taken place since Thursday.
If you see any recent avalanche occurrences or have any relevant snowpack information or photos, you can share them via the Public Observations link on the NZAA home page.
Since Thursday, 50- 60 cm of new snow may have fallen above 1800m. Below 1800 m, a significant amount of rain has soaked the snowpack before temperatures started to cool early Friday morning and finished with a possible 5- 10 cm at around 1300m. Strong north-west winds may have redistributed much of the new snow in exposed areas during the storm.
Previously, a small top-up of 4- 5 cm fell on the 18th, with strong south-west winds forming very small pockets of windloading just under ridgelines. Before this, gale westerly winds redistributed the 60- 70 cm of storm snow from earlier last week, mostly stripping west aspects back to hard ice or rock and loading east aspects above 2000m with 1-2m of dense snow. At around 1800m the snow depth is around 50-70cm and was capped by a supportive rain crust before the current storm.
Although the pack appears consolidated, in some isolated areas on mostly south-facing aspects above around 1900m, weak faceted forms may be starting to develop and should be monitored with future loading.
Saturday
A few showers falling as snow to 400 metres, then clearing to fine in the morning.
Wind at 1000 metres Southerly 40 km/h, dying out in the afternoon.
Wind at 2000 metres Southwesterly 50 km/h, dying out in the afternoon.
Wind at 3000 metres Southwesterly 50 km/h, easing to 30 km/h in the afternoon.
Freezing level 600 metres.
Issued: 1:03pm Fri 24 Jul
Below around 1700m on all aspects a slick rain crust may be hiding just under the surface.
Moderate
New Zealand Avalanche Advisory (NZ Mountain Safety Council)
