Snow conditions 13.2.2015

RISK ASSESSMENT



Avalanche danger is mostly degree 2.



The snowpack has somewhat stabilized, but remains locally potentially quite unstable and poorly bonded to the substrate. An avalanche can be triggered by increased loading of the snowpack. Steeper slopes and areas with wind-packed snow are particularly dangerous.

Spontaneous avalanching is not expected, only on steep, mainly grassy south-facing slopes can individual slab avalanches release in mid-day or early afternoon, possibly even ground avalanches.



SNOW CONDITIONS



On Wednesday sunny weather prevailed, the freezing level was at around 1900 m a.s.l. The snowpack therefore softened on south-facing slopes and mid-mountain plateaus during the day, and froze at night. This caused the crust to strengthen. On Thursday it was sunny only above around 1400 m, but temperatures were below zero. Thus, the sun's effect on south aspects was less. By today, temperatures have risen slightly at altitude again, positive temperatures in a layer of a couple hundred vertical meters at around 1500 m a.s.l. Above and below this warm layer, temperatures are below zero. Snowpack depth is quite uneven. At 2500 m a.s.l. up to around 180 cm of snow, at 1500 m up to around 100 cm, at 1000 m from 20 to around 60 cm.



CURRENT SNOWPACK STATE



The snowpack is dry, soft in sheltered shady spots, on more wind-exposed spots and on south-facing slopes and in mid-mountains quite crusty and locally hard. During the day on south-facing slopes and mid-mountain plateaus it becomes wet or softens, at night it refreezes. There are many wind slabs and slabs that remain relatively labile - lying on bare or icy ground, especially at higher elevations also on old crusty snow base.

Ridges are mostly quite wind-scoured and thus hard and icy in many places.



FORECAST WEATHER DEVELOPMENT



Today the snowpack will soften in the positive temperature layer on south-facing slopes and elsewhere on south aspects during the day, refreeze at night. In north aspects snow will mostly remain dry or frozen. Tomorrow clouding over in large parts of the Julian Alps and hills of northern Primorska and Notranjska. In the western part light snowfall will begin. Elsewhere still quite sunny, freezing level with southwesterly wind at around 1100 m a.s.l. On Sunday mostly cloudy and foggy, especially in Julian Alps and foothills occasional precipitation, snow line at around 700 m a.s.l. Especially in western half of Julian Alps up to around 20 cm snow may fall by Monday, which will bond poorly to the substrate and southwesterly wind will redistribute much of it into slabs.



SNOW CONDITIONS TREND



Avalanche conditions will not change much in the larger part of our mountains. On south-facing slopes snow will gradually consolidate and somewhat stabilize. New snow will slightly increase avalanche risk due to new slabs especially in western half of Julian Alps.



General avalanche danger is degree 2 on the European 5-degree scale.



MODERATE - due to wind-packed snow, slabs and weak layers in old snowpack.



Next report will be published on Monday, 16.2.2015 afternoon.



Source: ARSO