Avalanche hazard is rising as a series of cold fronts approach the region.
Time to give thought to what the current surface condition is- a wise man once said, 'todays snow surface could be tomorrows weak layer.'
Around 5-10cm of new snow is forecast overnight Tuesday above around 1500m with strong NW winds. Fresh windslab will develop around SE aspects and features. This will be landing on a variety of snow surfaces; from crust to old stiff windslab and shallow powder in sheltered areas.
A number of small loose wet avalanches ran on sunny slopes on the 17th.
Prior to this, there was an avalanche cycle during the storm on the 13th, 14th and 15th, with wind slab and storm slab avalanches on south and east aspects up to size 3 and loose wet avalanches on all aspects below around 1800m.
Late last week about 10cm of new snow fell above 2000m on the Divide. This covers snowfall from earlier in the week that was extensively distributed by gale NW and SW winds, leaving firm windpressed drifts in sheltered areas and slick crusts in more exposed areas. Below around 1800m the snowpack is capped with a hard rain crust. Faceting has been observed in shallow snowpack areas in the Malte Brun range as well as a buried graupel layer that appears un-reactive to snowpack tests. The lower snowpack appears to be well bonded, but we are continuing to monitor crust facet laminates in the lower pack in the eastern part of the forecast area.
Forecast
Showers, possibly heavy, with snow to 1500 metres, clearing in the morning but remaining cloudy.
Wind at 1000 metres
Northerly 45 km/h, dying out in the morning.
Wind at 2000 metres
Northwesterly 50 km/h, easing to westerly 30 km/h in the morning, rising to 50 km/h at night.
Wind at 3000 metres
Westerly gale 70 km/h, easing to 45 km/h in the morning.
Freezing level
1700 metres.
Exposed areas have been stripped back to a slick crust by strong NW and SW winds. Below 1800m there are icy rain crusts. Take an ice axe and crampons( and the knowledge to use them) for any travel above the snowline.
High
New Zealand Avalanche Advisory (NZ Mountain Safety Council)
