A NW storm is bringing high winds, rain and heavy snow, raising the avalanche hazard through Sunday.
Natural avalanches are likely during the storm and mountain travel is not recommended.
Trampers beware when crossing gullies and obvious avalanche paths. Safe travel is one at a time.
Significant snowfalls up to 1m at higher elevations will sharply increase the windslab hazard on slopes lee to the NW, where even higher accumulations may be found.
While these slope are mostly in the south-easterly half, winds can 'wrap around' terrain features creating hazards in unexpected places.
This weekend is a time for heightened vigilance and avoiding mountain travel.
Below 1200m and out of the wind new snow will fall more uniformly across all aspects. In the alpine, much of the new snow will also fall on snow grass and other sliding surfaces that increase avalanche hazard.
Trampers beware of crossing steep, newly-laden snow slopes and take care when crossing avalanche paths and gullies.
A small loose wet avalanche cycle played out this week ahead of the new storm.
Park user observations provide important information. Please help us.
If you see anything, please report it in the public observations section of the NZAA website.
Up to 60cm of snow fell at higher elevations in western parts of the Park on Saturday afternoon, with snow and rain totals tapering quickly to the east. Strong to gale winds from the northerly half will have formed windslabs on south facing slopes and around terrain features. The underlying snowpack is well consolidated and early rain below ~1800 will have improved the bond to old surfaces. The threshold for avalanches ahead of the incoming storm was estimated at around 1500m in the west, tapering east, but new snow will fall overnight down to an estimated 700m.
Forecast for Sunday 23 August
Heavy rain, turning to showers with possible squally thunderstorms in the morning as snow lowers to 700 metres, easing in the evening.
Wind at 1000 metres
Northwesterly gale 85 km/h, easing to westerly gale 65 km/h in the afternoon.
Wind at 2000 metres
Northwesterly severe gale 120 km/h, easing to westerly severe gale 100 km/h in the afternoon.
Freezing level
2000 metres, lowering to 1200 metres in the morning.
Elevated sliding danger currently exists throughout the Park ahead of the storm, but mountain travel should be limited this weekend. If you must travel ahead of the storm, ice axe and crampons are essential.
Moderate
New Zealand Avalanche Advisory (NZ Mountain Safety Council)
