Issued: Apr 18th, 2023 4:00PM
The alpine rating is Storm Slabs., the treeline rating is , and the below treeline rating is Known problems include
Dial back your terrain choices where you are finding more than 20 cm of new snow. Avoid wind loaded areas where slabs are deeper, more cohesive, and are likely reactive to human triggering.
No new avalanches were reported in the region on Monday.
We expect backcountry users will see evidence of a large avalanche cycle from last week's rain event when numerous wet loose avalanches reached the valley bottom.
If you head out in the backcountry, let us know what you are seeing by submitting a report to the Mountain Information Network.
In the alpine and around treeline, 20-40 cm of snow covers a frozen crust.
The mid snowpack is generally settled and strong, except in areas with snow depths less than 150 cm. In these lower snow areas, the mid-pack is likely weaker and more faceted.
Below treeline, expect to find moist or refrozen surfaces, and a shrinking snowpack that is isothermal during the heat of the day.
The lower snowpack includes a layer of weak sugary crystals near the ground. This layer has shown signs of gaining strength, and it has not produced recent avalanche activity in this area.
Cloudy with flurries, bringing 6-12 cm of new snow to the alpine. Northwest ridgetop winds increase from light to moderate early evening. Freezing levels 1000 m. Treeline low -6 °C.
Cloudy with flurries, 3-9 accumulation. Moderate northwest ridgetop wind. Freezing levels 1500 m. Treeline high around -5 °C.
Overnight flurries continue bringing, 7-10 cm of new snow to the alpine.
Cloudy with scattered flurries, 5-10 cm of snow is expected in the alpine. Moderate northwest ridgetop wind. Freezing level 1700 m. Treeline high around -1 °C.
Mix of sun and cloud with isolated flurries, trace accumulations. Light southwest ridgetop wind. Freezing levels rise from valley bottom to 2000 m by mid-day. Treeline high 0 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Storm slab size and sensitivity to triggering will likely increase through the day.
- Be carefull around freshly wind loaded features.
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
Strom slabs will be most reactive in areas that receive higher snowfall amounts and on steep, wind exposed slopes where new snow is more likely to form a cohesive slab. Use caution around leeward terrain features where deposits are deep.
In southerly facing terrain expect new snow to overlay a melt freeze crust, providing an ideal sliding surface for storm slabs.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Valid until: Apr 19th, 2023 4:00PM