Some primo powder fell overnight with around 20cms in town and 35cms or so on top got me excited but the visibility on top of Goryu meant it was just pointing the board in a direction I hoped was down and hoping for the best…seriously only 2 or 3 metres visibility up there. The powder is great, light and dry, if you’re somewhere with better visibility you’ll have a sick day out there.
SNOW STABILITY INFORMATION (AS AT WEDNESDAY 18TH):
The February 15th ice crust has formed to be anywhere from 2 ~ 5 cm thick across the mountains and is locking everything down below it. The interface between the ice and the new snow is proving very unstable in snow tests and slope tests. There have not been many natural avalanches noted but with the sudden decrease in air temperature the chance for faceting at the ice / new snow interface is high. This would mean that the snow resting on top of the crust could become easier to fracture and create an avalanche. Most likely soft and firmer wind slab avalanches depending on aspect to wind and sun. Yesterdays solar radiation has created a thin melt freeze crust at the surface on solar aspects that will become buried with new snow today and tomorrow.
Stability Tests:
Feb 17th
South aspect on Happo One @ 1915 metres elevation on a 32 degree slope @ 14:55.
CTE(3)RP down 7cm
CTM SC down 45cm (irregular shear) @ ice / new snow interface
CTH(21)SC down 45cm Same layer as above
Test pit back wall ski cut found SC results on a knee shock (like a RB2 or AK Block 2)
North aspect on Nishi Hiyodori @ 1910 metres elevation on a 35 degree slope
CTE(1‚3)RP down 45cm @ ice / new snow interface.
Travel Advisory:
Travel in unsupported steep terrain with the 30 plus cm of new snow on top of the rain crust should be avoided until bonding of the new and old snow layers takes place. Recent cold weather is supporting the creation of facets at the ice crust / new snow interface. Areas below tree are still retaining the warmth from the rain and warm weather aand solar radiation could rapidly loosen the present wet isothermal snow pack. With this in mind it is still possible that weak layers with in the wet snow may produce a wet slide when with warm temperatures or solar radiation. Slides with in the new snow once snow amounts increase is also a concern. New snow on the Feb. 18th sun crust may also prove to be a concern with increased snow fall
Avalanche Hazard Rating:
Below Tree Line: Moderate trending to Considerable with warming.
Tree Line: Considerable
Alpine: Considerable trending to Poor with faceting at crust / new snow interface and added snow and wind effect at elevations above freezing level.
Rapid air temperature decrease
Cornice fall
Use caution if crossing solar radiated slopes.
Increased instability of solar aspect start zones especially under cornices and very steep slopes.
Increased caution advised around rocky outcroppings‚ cliffs and well spaced trees in start zones.
Development of cornices in lee slopes
Lee side loading
Windward scouring of ridges and rock out-crops creating uneven loading of slopes
Due caution on cross loaded slopes
Poor bonding at or around buried crust
Facet layer around buried crust
Wide propagation due to wind slab
Stay away from steep and convex terrain
Danger level 3 : Considerable
Natural avalanches possible. Human triggered avalanches probable.
Danger level ratings are set for conditions at tree line
and may vary from below tree line and High Alpine areas.
Use this information as a guideline only.