Avalanche Forecast

Good - The weather pattern is stable

Conditions will remain dry and mild through the forecast period with what we call diurnal fluctuations in the freezing level (the spring-like pattern where the temperature can drop by up to 10 degrees overnight only to rise again through the day). Thursday will see mainly cloudy skies with light westerly winds and a freezing level rising from 1000 to 1800m. Dry conditions will continue into Friday although an increasing North to North East flow may bring isolated flurries overnight, the freezing level will reach a high of 1500m. This pattern continues into Saturday with up to 5 cm of dust on crust expected.

Things appear to be locked up tight and no new avalanches have been reported in the last couple of days.

The upper snowpack has been undergoing a daily melt-freeze cycle for the last couple of days especially on sun-exposed slopes. Surface hoar has been reported to be growing around Nelson. While the overnight freeze can cap the snowpack protecting buried instabilities, daytime warming can make upper slabs less stiff meaning that deeper weaknesses may be more susceptible to triggering. The crust buried at the beginning of February is down around 40-60 cm and is generally well-bonded to the overlying slab; however this bond is much weaker where surface hoar overlies the crust. Below that, recent snowpack tests suggest that the mid-January surface hoar layer could still produce an avalanche given a large enough trigger. It can be found about a meter down in the alpine and 50-60cm down at treeline. The mid-December crust/facet/surface hoar weakness may persist in the mid to lower snowpack at higher elevations.