Tuesday's wind will continue to add to windslabs above about 1800m.
Wet loose avalanches are possible at lower elevations.
There is a high uncertainty about the amount of precipitation and the freezing levels for Tuesday. It is best to take a cautious approach until the storm is over.
Gale north-west winds will build windslabs on south, south east and east facing terrain.
The various weather models show a lot of variation in the amount of precipitation and the freezing level. Therefore, exactly how big and at what elevation the new windslabs will form is uncertain.
Windslabs could be easy to trigger due to weak surface crystals caused by the recent fine weather.
Take care to identify and avoid recent windloaded terrain.
Warmer temps could bring on a loose wet cycle, particularly in the north where light rain is expected below about 1800m.
Further south the dry wind may keep the problem from developing.
There's a lot of snow on the northern half, so these could get quite large given a big enough slope that rapidly warms.
Watch for signs of rollerballing. Consider what is above you and where you would end up if caught.Be prepared to change you plans if you see signs of significant warming.
Low
Multiple small loose wet avalanches were reported in steep terrain in the Camp Stream and Coal river catchments on Saturday and Sunday. 1800m -2000m NW facing slope.
Current avalanche observations are limited due to the storm.
If you see any activity on the Two Thumb Range, please make a public observation. It really helps us to produce accurate forecasts.
Severe gale NW winds have stripped snow from windward slopes and deposited it onto south, southeast and east facing terrain.
The north of the range received about 15cm of new snow above about 1800m on Monday, tapering to only 5cm mid range and nothing at the southern end.
Below about 1800m, the precipitation fell as rain.
Snow depths in the south are about 70cm, tapering to about about 50cm mid range and 40cm in the north.
The snowpack north of Stag Saddle is not well understood, with no direct observations.
Isolated showers, becoming widespread in the afternoon and evening.
Wind at 1000 metres
Northwesterly gale 65 km/h, rising to severe gale 110 km/h in the morning, easing to westerlies 45 km/h at night.
Wind at 2000 metres
Northwesterly gale 75 km/h, rising to severe gale 120 km/h in the morning, easing to westerlies 60 km/h at night.
Freezing level
2500 metres.
The wind has stripped the soft snow back to exposed crusts. Sliding danger will be patchy with lots of rocks in the runouts. Take extra care.
New Zealand Avalanche Advisory (NZ Mountain Safety Council)
