Fiordland

This is a spring of fast changing freezing levels. On Monday morning expect snow from the NW down to about 1600m after a warm dry night with freezing levels above 2000m. Light snow will fall over the day, to about 1600m, accompanied by gale NW winds. Monday evening has some heavy precip forecast

The snowpack is largely stable, with possible slab avalanche conditions up at 2200m or above.

Travel should be largely safe, although unpleasant. Monday evening has heavy precip forecast, and will be different case.

Fiordland National Park Forecast for Mon 21st.

Showers, turning to rain in the morning, possibly heavy, then easing to isolated showers in the evening. Snow to 1200 metres, raising to 1900 metres in the afternoon.

Wind at 1000 metres - Northwesterly 40 km/h, but gale 80 km/h south of Secretary Island, becoming northerly gale 80 km/h but severe gale 105 km/h in the south in the morning, easing to westerly 60 km/h everywhere in the evening.

Wind at 2000 metres - Northwesterly gale 75 km/h, rising to severe gale 110 km/h before dawn, then easing to southwesterly 60 km/h in the evening.

Freezing level - 3000 metres, but 1400 metres about the Fiords, becoming 2000 metres everywhere in the morning, then lowering to 900 metres in the evening.

Issued: 1:28pm Sun 20 Sep

Moderate

• We are uncertain due to a limited number of field observations.
• We are uncertain about forecast rain amounts.
• We are uncertain due to rapidly changing freezing levels.

20Sept - Little evidence of natural storm activity seen in the Homer area.

17th Sept- overflight from Te Anau to Milford track and across to the Routeburn- probably 40 or 50cm down to about 1800m and much less down to about 800m. Lots of evidence of loose snow activity during the storm. Slabs up high were difficult to spot with wind transported snow having refilled the crown walls.

16 Sept - no observers in the terrain. Expected some activity.

12 Sept - Numerous small size 1 loose dry and loose wet avalanches from a day or two earlier during/following the storm. Gertrude Saddle area

10 Sept - A storm slab avalanche cycle (up to sz 2-2.5) was noted from shaded aspects, many initiating at mid-path elevations with long shallow crown-lines suggesting surface hoar or facet forms present. This is in the Darran Mountains.

19 Sept- Up to 50cm snow from the west fell to about 1900m, with rain and snow below that. Expect dry snow above 1900m and wet and rain soaked snow below that.

16 Sept - Around 50 cm fell above about 1900m. Lesser amounts fell below that down to around 800m as temperatures cooled when the front passed.

From 12th Sept - Gertrude saddle area. About 100cm snowpack depth at the 1400m, up to 180cm in sheltered areas. Snowline around 1000m. Surface conditions were a light dusting on top of a thick ~5cm rain crust above 1200m. The Sept 4 melt freeze crust was found approx. 25cm down. Well consolidated below that.

9th Sept - est about 20-30cm at higher elevations, with 10-15cm at 1100m, with strong SW . The Sep 9 precip event brought varied amounts (10-35 cm) of new snow in the Darran's.

7th - 8th Sept No precip, clear weather

Observations from 8 Sept in the Darran's showed a wind affected upper snowpack with some exposed areas scoured back to a frozen surface (4th Sept rain crust, at about 1900/2000m and lower). Most areas had a thin melt-freeze crust over lighter drier snow over the thick rain crust (4/9). Developed surface hoar was evident at most shaded sites. Below the older rain crust, (around 1900/2000m and lower) was moist snow to deeper levels. A melt -freeze cycle was evident on sun affected slopes in the top 1-3 cm.

Take an ice axe and crampons if you are out exploring, but don't go exploring on Saturday.