Avalanche Bulletin from Wednesday, 03/21/2018, at 7:30 AM
WHY? - Danger patterns (dp):
Avalanche danger still considerable regionally. Beware fresh snowdrifts!
Avalanche danger in Tirol’s backcountry touring regions is often moderate, but still considerable from region to region. The main peril stems from freshly formed snowdrift accumulations: they are generally small, but poorly bonded with the snow base beneath them. Thus, avalanches can frequently be triggered by even minimum additional loading. Avalanche prone locations are found on steep slopes and in ridgeline terrain above 2200 m, especially in W-N-E aspects. The low temperatures have helped the threat of gliding avalanches to recede. On steep, grassy slopes below 2400 m, their risk still requires special caution.
Over the last few days there has been 20-30 cm of fresh snow registered widespread in Tirol, up to 50 cm in the Ötztal and Stubai Alps, from place to place more. The N/NE winds at high altitude were generally light to moderate. But since the fresh snow was so dry and loose, snow transport occurred nonetheless. The snowdrifts were deposited on loosely-packed fresh snow. The bonding is poor, the proneness to triggering high. In isolated cases, inside the old snowpack are weak layers in the form of faceted crystals beneath thin melt-freeze crusts.
Alpine Weather Forecast (ZAMG-Weather Service Innsbruck)
Weather. Caught between a low over the Mediterranean and a high over western Europe, the Alps are in the grips of a northernly air current bringing cold continental air masses our way. A weak perturbance will push moist air masses to North Tirol today; as of tomorrow, the air will dry out. Overall, Tirol will primarily feel the effects of a weak high through the weekend. The cold will reach its climax tomorrow, thereafter it will become milder. Mountain weather today. Icy cold, made more intense by the wind. Visibility often impaired by clouds and fog, some light snowfall could result. The air at high altitude is becoming drier, which in turn will bring a mixture of sunshine and convective cloud this afternoon. The Southern Alps are bathed in sunshine as a result of northerly winds. Temperature at 2000 m: -13 degrees. at 3000 m: -19 degrees. Moderate to strong, icy cold NE winds at high altitude.
Avalnache danger will slowly decrease.
[Author: Rudi Mair]
[Translated by Jeffrey McCabe]