It goes without saying that this is a complex storm!
Further natural avalanche activity is expected, especially at upper elevations, as rainfall begins to fall on new snow.
Avoid avalanche terrain if at all possible.
Loose Wet avalanches will be likely on all aspects and elevation bands. Look for roller balling or recent avalanche activity as a key sign of instability, and avoid avalanche terrain as temperatures rise and rainfall begins.
Wind Slab avalanches are possible at upper elevation bands across the SE 1/2. Strong NW wind will transport recently fallen snow. Although the new/old bond is suspected to be good, instabilities within the new snow and what is being blown around are whats worth paying attention to.
A Wind Slab and Loose Wet natural avalanche cycle likely occurred on all aspects below 1800m on Thursday afternoon. At this stage, observations are limited, but it is suspected this was up to size 2- 2.5.
25mm of rain fell to ridge top before 35cm of snow fell to around 1300m by 6pm Thursday. This new snow is being redistributed into slabs up to 60cm deep across the S 1/2. A relatively saturated and unconsolidated upper snowpack existed prior to snowfall beginning. Any evidence of previous rain crusts was hard to find, as they had broken down at most elevation bands and on most aspects. The exception to this was high on the S 1/4, where some evidence of them being intact was found. Lower in the pack was very well consolidated.
With the FAFL expected to increase from 2000m up to 2800m by Friday afternoon, this storm is certainly going out warm. Gale NW winds and a further 15mm of rain on snow is forecast.
No sliding hazard currently exists in the Hutt Range.
Moderate
New Zealand Avalanche Advisory (NZ Mountain Safety Council)
