Weisseck, Muhr Valley

Danger zones in shallow-snow transitions and steep ridgeline slopes

Danger zones in shallow-snow transitions and steep ridgeline slopes

Caution is required in transitions in shady and high-alpine steep terrain, where large additional loading can trigger AN OLDER SNOWDRIFT MASS, then grow to a medium-to-large sized avalanche. Most danger zones are in W/N/E aspects distant from ridges and in steep gullies. The fresh snowdrifts in E/S/W facing ridgeline terrain are generally thin, the biggest risk is being forced to take a fall.

Loose powder (15-25 cm) lies atop a compact old snowpack surface. Near ridges the surface is wind-impacted, this influence increases with ascending altitude. Thin, soft snowdrift masses often are deposited atop soft layers. Older snowdrift accumulations from last week are still instable on extremely steep slopes, as several triggerings showed over the weekend. Hidden, more deeply embedded faceted-soft layers are unlikely to trigger.

On Thursday, very sunny, outstanding visibility, few clouds, winds will intensify slightly (30-40 km/hr) from N/NW. At 2000 m: -5 to -3 degrees. On Friday, unimpeded sunshine. Convective cloud build-up starting at midday, but it will remain dry. Cold northerly winds in exposed terrain (30-40 km/hr). At 2000 m: -10 to -7 degrees.

The trigger-sensitivity of the old snow will recede. Otherwise, no significant change is expected.