Avalanche Forecast
Issued: Mar 23rd, 2018 3:56PM
The alpine rating is Storm Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeFresh slabs overlie an old crust on most aspects, and buried surface hoar on north aspects in the alpine. Assess the bond between the new snow and the old surface before committing to bigger slopes.
Summary
Confidence
Moderate - Due to the number of field observations
Weather Forecast
TONIGHT: Cloudy, flurries. Accumulation up to 5 cm. Ridge wind moderate, southwest. Alpine temperature near -10. Freezing level lowering to 500 m.SATURDAY: Cloudy, flurries. Accumulation 5-10 cm. Ridge wind light to moderate, southwest. Alpine temperature near -8. Freezing level 1200 m.SUNDAY: Increasing cloud in afternoon. Ridge light, southwest. Alpine temperature near -5. Freezing level 1500 m.MONDAY: Increasing cloud in afternoon. Ridge wind light, southwest. Alpine temperature near -5. Freezing level 1500 m.
Avalanche Summary
Reports from Thursday included activity in the recent storm snow including sloughing and small (size 1) storm slab releases from 10 - 20 cm thick above the most recent crust.Prior to Thursday storm there were no significant avalanche observations to report from earlier in the week.
Snowpack Summary
Around 10 - 15 cm of new snow has fallen with moderate southeast wind. This snow sits on a mixture of weak grains including a slippery crust that is present at all elevations on solar aspects and all aspects below 1900 m elevation. On northerly aspects at and above treeline the new storm snow is burying a mix of large surface hoar and surface facets.Two other weak layers are present in the upper snowpack. The mid March interface is down 20 to 30 cm and it resembles the old surface; crust on solar, surface hoar on high elevation north.The early March interface is 35 to 50 cm below the surface and is similar in composition to those listed above.A few other persistent weak layers are buried in the mid and lower snowpack, but they have gone dormant and are unlikely to resurface until we move into a period with consecutive above-freezing nights later in the spring.
Problems
Storm Slabs
Southwest wind combined with snowfall through Friday will form fresh slabs that are not expected to bond well to the mix of crusts, surface hoar and facets now buried. Watch for wind slabs in unusual locations.
Use caution in lee areas in the alpine and treeline. Storm snow and wind have formed touchy slabs.Use caution on open slopes and convex rolls
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 24th, 2018 2:00PM