The hot and sunny weather persists on Thursday, which will likely continue the natural avalanche cycle. The danger will be the highest when the day heats up, so make sure you are completely out of avalanche terrain, with no overhead exposure.
Weather Forecast
WEDNESDAY NIGHT: Clear skies, light southeast wind, alpine temperature 6 C, freezing level 3300 m.THURSDAY: Clear skies, light southeast wind, alpine temperature 5 C, freezing level 3000 m.FRIDAY: Partly cloudy skies, light east wind, alpine temperature 4 C, freezing level 2800 m.SATURDAY: Cloudy with light rain and snow in the high alpine, accumulation 2 to 5 mm, light east wind, alpine temperature 0 C, freezing level 2200 m.
Avalanche Summary
The wet loose avalanche cycle continued on Tuesday, producing small to large (size 1 to 3) avalanches on southeast to southwest aspects. The avalanches were at all elevations. There were also a large slab avalanche that released on a south aspect at 2400 m, possibly releasing on the weak layer described in the snowpack summary.This avalanche cycle is expected to continue, as temperatures remain exceptionally warm and the sun shines strong.
Snowpack Summary
The warm air and sunny skies have produced moist snow to ridge top on all aspects. The upper 40 to 60 cm of snow may slide easily during the day, either as loose wet snow or as a cohesive slab, as it sits over weak faceted grains or a melt-freeze crust on sun-exposed slopes. The moist snow may freeze into a melt-freeze crust overnight.Below treeline, a weak layer of faceted grains and/or feathery surface hoar crystals buried in mid-January may be found around 70 to 120 cm deep. Although this layer has been dormant for a few weeks, the current warm conditions may awaken this layer. Steep cutblocks and large open glades at lower elevations are the most likely places to trigger this layer.The lower snowpack is generally consolidated and strong. The exception is around thin, rocky areas in the alpine, where the snowpack is composed of faceted snow. The warm air and sunny skies could trigger very large avalanches that could run to the valley bottom.
Problems
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.