Fiordland

Gale winds and new snow is in the forecast for Thursday and Friday. The freezing level lowers during Thursday.

The avalanche danger will increase to Considerable over the next couple of days.

Avoid avalanche terrain during the storm

Observations from Milford Track area, Darran's and Routeburn on 20 July -Slick frozen conditions below 17/1800m. Only the highest peaks (North Peak, Talbot, Mt Christina) had some slopes with enough snow to cover terrain features and look wind loaded.

From 21 July - Below around 1800m the thin snowpack had a mixture of rain and snow over the week of 13th to 18th July, culminating in rain up to about 1750m on Saturday the 18th. This snowpack is generally thin, with much of it still below avalanche threshold, and rainsoaked and refrozen.

Above about 1800m there has been about 80 or 90 cm fall in northern Fiordland and about 60cm in the south, from a series of westerly fronts over the week of 13th to 18th July. There were warm temperatures on Saturday 18th and this snowpack is now thought to be stable, with possible remaining wind slab at the high elevation areas lee to the west but should be treated cautiously as there have been not observers in the field.

Rain, heavy at times. Possible thunderstorms and hail from afternoon. Snow lowering to 1300 metres in the afternoon and evening.

Wind at 1000 metres - Northwesterly gale 70 km/h, rising to severe gale 90 km/h for a time in the afternoon, then easing to 50 km/h in the evening.

Wind at 2000 metres - Northwesterly severe gale 100 km/h easing to gale 70 km/h in the evening.

Freezing level - 1800 metres, lowering to 1300 metres in the evening.

Some new snow may change surface conditions. At the moment the snowpack below about 1700 is fast and hard. Take an axe and crampons if you're exploring.

Moderate

• We are confident the likelihood of avalanches will increase with the forecast weather.
• We are uncertain about forecast snowfall amounts.
• We are uncertain due to variable freezing levels.