Storm problems will persist on Monday, especially at higher elevations. Conservative decision making remains critical and travel in avalanche terrain is not recommended.
Summary
Confidence
Fair - Freezing levels are uncertain on Tuesday
Weather Forecast
The last major frontal system will reach the interior Sunday overnight but it looks like it will track south of the Cariboo region. On Monday, the region is expected to see 4-8mm of precipitation. Forecasting the freezing levels for the Cariboos is quite difficult for the next couple days as there is some disagreement in the weather models. Freezing levels may drop to near valley bottom Sunday overnight. On Monday, I expect freezing levels to be around 1500m but they could potentially be quite a bit lower. Alpine winds are expected to be light-to-moderate from the SW on Monday. On Tuesday, things should dry out as a ridge of high pressure builds but mostly cloudy conditions are expected and lingering flurries are possible. Freezing levels are again uncertain for Tuesday but I suspect they will stay around 1500m. A mix of sun and cloud is expected for Wednesday with unseasonably high freezing levels persisting. However, during the overnight periods, temperatures may drop and we may see spring-like diurnal temperature cycles.
Avalanche Summary
A widespread natural cycle to size 3.5 has been reported between Friday and Sunday. This includes both storm slabs and persistent slabs. Avalanches are expected to be starting dry and ending wet, potentially running to valley bottom. On Monday, natural avalanches remain likely at upper elevations where storm and wind loading continue. At lower elevations which have seen rain, natural activity is less likely but remains possible. Human-triggering remains very likely at higher elevations on Monday.
Snowpack Summary
50-80cm of recent storm snow has fallen over the late-Jan weak layer at higher elevations. Rising freezing levels during the storm have created upside-down snow conditions and highly reactive storm slabs. Rain has soaked the snow surface up to around 1700m and moist snow is reported to at least 2000m. Strong SW winds have formed wind slabs in exposed leeward terrain features. The storm slab sits on an old rain crust at lower elevations, variable surface hoar, and/or wind affected surfaces at higher elevations. Multiple weaknesses within the storm snow are also expected. The mid-January surface hoar is typically down 80-120cm and is still reactive in some areas. The mid-December weak layer is down over 120cm. It has generally been unreactive but may wake-up with the new storm loading.
rbuhler,
Avalanche Canada
