TREND: IMPROVING / ONGOING / DETERIORATING
The snow has missed a refreeze last night below 1800m, however the freeze thaw cycle has been strong for the previous 5 nights and everything is still unseasonably fat. Those afternoon solar aspects below 1750 have all burnt off including ridgetops. So some of the traverses like The Razorback and Eskdale are getting thin and patchy in places.
We are currently looking towards a fresh top up in the 2cm - 5cm range (10cm-15cm on leeward aspects). This top up of snow looks to be comparatively ‘gentle’ on approach. Meaning that the precipitation is not associated with the usual 50km+ prefrontal wind. And as such, without transport the usual wind slab hazard will have little to get established. That said, this time last year BOM called 5cm and we got 20cm and this snow went straight from benign to high danger in the space of about 4hrs, with easy results, shooting cracks, pin-wheels and small natural slides. The increase of heat energy in the system in Spring makes it more volatile and as such hard to confidently forecast. If your out on saturday a cautious approach will be prudent in the event that we (The Bom and MSC) got it wrong…
Beyond this precip event we’ll see the return of the freeze / thaw cycle into the foreseeable future and with that sees the return of the wet slide activity. This problem is particularly acute on the North aspects at higher elevations, and generally anywhere else below 1750 where there is still lots of snow. The clear warning sign is ski petration to ankle depth on inclines over 25˚. There is a subtle persistent weakness between softer saturated snow and the still mending shield ice from a ‘deep freeze’ (-7˚) back in August at around 20cm. We have had a few reports of people swept in these slow-mo slides. Nothing critical but unexpected for the victim, in how far they travelled, with no control or the ability to escape the heavy wet carriage.
Finally, also, for a few unlucky travellers (split boarders in soft boots & 75mm telemarkers) marooned on ice aspects without the confidence to ‘ride it out’ or the safety of an axe/crampons to anchor, there’s been a couple of mini rescues reported across the range. This hazard is real, whilst we have issued warnings on it from July 18th, and an understandable amount of ‘Warning Fatigue’ has kicked in, crew are being caught out. Subtle changes in geography and apparent solar exposure can create dramatic contrasts in surface conditions, even within the width of a turn. Compounded by the ‘Camo Snow’ of the mid september deposition.
With a 1.5m snowpack (3m on windloaded aspects) we are urging people to be careful and stay well clear of the cornices. With rapid warming or rain they will become prone to collapse.
The information provided here deviates from the standard reporting format that we apply to the travel advisory. It sometimes shows recent field obs results and images. It is pitched at participants looking for more detail.