Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Regions
South Coast.
Stormy, wet, and mild weather (a pineapple express) will maintain high avalanche danger on Thursday. It's best to wait out the storm or stick to simple, low-angle slopes.
Confidence
Fair - Due to the number of field observations
Weather Forecast
Summary: Mild and wet on Wednesday and Thursday following by cool and dry for Friday and into the weekend. Thursday: 15-25 mm Weds night and 30-45 mm on Thursday. The freezing level is near 2000 m. Ridge winds are moderate to strong from the southwest. Friday: Possible lingering flurries. The freezing level drops to around 500 m. Winds ease to light or moderate. Saturday: Mainly sunny. The freezing level is at valley bottom and ridge winds are moderate from the N-NE.
Avalanche Summary
No avalanches have been reported. It's very likely that there was a relatively large natural avalanche cycle early on Wednesday as temperatures spiked and heavy snow turned to rain. Please let us know what you're seeing out there at [email protected].
Snowpack Summary
As we begin our forecasting season, we are working with limited information from the field and base our forecasts primarily off weather station data and forecast weather. In the past 24-48 hours we have seen 40-60 cm of snow fall right down to 1200 m. Early on Wednesday temperatures spiked and it's possible that snow changed to rain all the way up to 2000 m (maybe higher). This recent snow (and rain) may overload a suspected buried weakness (surface hoar, facets and/or a crust) which developed during November's dry spell. This weak layer may be lurking down 60-100 cm. Check the bond of the snowpack at this level and take a cautious approach as new snow builds deeper above this layer.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
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.