Winter still reigns in the mountains
Since the end of April, extremely variable, moist and unseasonably cold weather conditions have prevailed.
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| An atypical “melting display” for this juncture of the season: increasing snow depths in May at 2060 m altitude in the Tux Alps. In addition, the plummeting temperatures at the end of April are visible, including subsequent, highly variable weather. |
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| The overall snow depths in Tirol’s mountains are above average for this juncture of the season. |
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| A typical picture of Tirol: lush green in the valley, satin white in the mountains. |
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| For comparison: a picture from the Lienz Dolomites in East Tirol (photo: 07.05.2019) |
Fresh snow reacts very rapidly to diffuse radiation and rising temperatures in this season. For that reason, over the last few days numerous loose-snow avalanches were observed releasing from rocky terrain and glide-snow slides and avalancahes over grass-covered slopes which were already bare in April and have now been blanketed in deep snow.
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| Loose-snow avalanches in “Inner Floiten Valley” in the Zillertal Alps (photo: 07.05.2019) |
In the very brief time windows, the true snow fans were able to enjoy fantastic powder-snow adventures.
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| No, not an error. This photo was taken on 7 May, showing the ascent tracks towards the Marchreisenspitze in the Kalkkögeln... |
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| ...a similar photo from 5 May, in southern East Tirol, en route to the Golzentipp. |
Wintery character persists
According to weather forecasts of ZAMG, conditions can be expected to remain variable and unseasonably cold. Tomorrow, Saturday the 11th of May, a cold front will arrive, bringing hefty rain showers, isolated thunderstorms and intensifying winds. The snowfall level will descend to intermediate altitudes, it is expected to lie between about 1000 m in northern regions and at 1400 m on the Main Alpine Ridge on Sunday.
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| In the mountains it will remain wintery. |
Caution: avalanches
Following the expected snowfall, we will be able to observe a very similar pattern, compared to what has happened with recent snowfall: numerous naturally triggered loose-snow avalanches, increasingly frequent slides over grass-covered slopes. Whoever is en route at high altitudes and in high alpine regions needs to expend special care towards the freshly-generated snowdrift accumulations in the regions where precipitation is heavy, especially in very steep terrain adjacent to ridgelines. The weak layer will tend to have graupel in it, as can be deduced from weather forecasts, as well as covered powder snow. Surface hoar near ridgelines (Nigg), particularly in shady ridgeline terrain cannot be ruled out, but will probably be eliminated by wind impact before it becomes a real threat.
Comparably more dangerous are the faceted weak layers which have formed since the end of April as a result of the danger pattern cold-on-warm. They are now covered over by deeper layers of bonded snow and continue to be prone to triggering. We assume, based on our own observations and incoming reports, this will apply to altitudes above about 2700 m. Initially, rather the shady slopes will be touched, with increasing altitude then to an increasing degree also west-facing, east-facing and south-facing slopes. This is a treacherous, not-to-be-underestimated threat of slab avalanches, especially because the fracture zones are area-wide and avalanches ultimately can grow to dangerously large size for backcountry skiers.
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Slab avalanche in “Inner Floiten Valley” in the Zillertal. North-Northwest 2700 m (We received additional reports of avalanches on 7 May from Main Ridge NE at 3000 m, E at 2900 m and SE at 3150 m). (photo: 07.05.2019)
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