Thursday, 5 December 2019

Ongoingly favourable avalanche situation

The favourable avalanche situation in Tirol persists. Even the weak cold front which is expected to brush Tirol on 7 December will not change anything significantly through Sunday, 8 December. The intensifying wind at high altitudes might generate fresh, relatively small snowdrift masses. These will sometimes be relatively easy to trigger, but can be easily recognized by practiced backcountry skiers and freeriders.

Danger level map for Thursday, 5 December 2019. Avalanche danger is frequently low.

Stable snowpack over widespread areas

What is currently most striking is the big difference in snow depths between northern and southern regions of Tirol. In the north, generally little snow; in the south, snow depths are noticeably above-average for this juncture of the season.

Snow depth measurements of our observer Hansjörg Schneider in Obertilliach. To date, maximum, average and minimum depths, along with current depths...and measurements go back to 1961!

Our evaluation of danger is based on the structure of the snowpack. Examinations of the snowpack continue to show a stable snow cover over widespread areas without any pronounced weak layers.

Snowpack analysis below Pfaffenkogel in the Stubai Alps (photo: 28.11.2019) 

Snow profile at the location cited above, at 3110 m, northwest, 25 degrees. Lower base: glacial ice. On top of that, compact layers of old snow influenced by melting processes. The bonding of the layers is good. Atop that, a very compact snow mass from the heavy snowfall of mid-November 2019.

On very steep, sunny slopes there are frozen water channels inside the snowpack in some places. Rietzer Griesskogel, Stubai Alps. (photo: 03.12.2019)

Snow profile, Axamer Lizum, 2120m, W, 25 degrees. What is interesting is the currently loosely-packed, cold snowpack surface. Clear nights facilitate expansive metamorphosing of the snowpack surface. For future snowfall, this then becomes a potential weak layer.

At high altitudes the snowpack is frequently wind-impacted, and thereby, hard. The snowpack surface hardens through melting and refreezing, also at intermediate altitudes on very steep, sunny slopes. (photo: 25.11.2019)

Review of the last week

Snowfall in westernmost regions

Most striking was the snowfall on 29.11 and 30.11 in the furthermost western regions. Snowfall was heaviest in the Arlberg and Galzig regions, about 50 cm. Elsewhere, from the rear Paznaun Valley into the western Lechtal Alps, often between 20 and 30 cm of fresh snow, with swiftly decreasing amounts moving to the east.

On Galzig, 50 cm of fresh snow. Since then, continually diminishing snow depths as a result of dry winter weather since Tuesday, 3 December.

Little avalanche activity

As a result of the fresh snow and wind at high altitudes, small snowdrift accumulations were generated in the western regions.  For a brief period these were relatively easy to trigger. These accumulations were especially prevalent behind abrupt changes in the terrain.

Small slab avalanche on the way to Hohen Kopf above the Friedrichshafen Refuge. (photo: 30.11.2019)

Small slab on lee slope near ridgeline below a cornice, Pitztal. (photo: 30.11.2019)

Small loose-snow avalanche from rocky terrain in Lechtal. (photo: 30.11.2019) 

Glide-snow slide in rear Ötztal. (photo: 30.11.2019)

Old glide-snow fracture in East Tirol. (photo: 03.12.2019)

Gliding snow over smooth rock slabs in Stubai Alps. (photo: 26.11.2019)

Steep-slope enthusiasts are getting what they seek

The favourable avalanche situation is being enjoyed to the fullest  by steep-slope specialists in the regions of the south where snowfall has been heaviest. Snow from the heavy snowfall in mid-November “sticks” to the extremely steep snow base.

En route in the Lienz Dolomites. (photo: 27.11.2019)

Also in the Lienz Dolomites. (photo: 27.11.2019)

A good time for safety training

The perfect time for a safety check is at the launch of winter: equipment and functional safety training of avalanche backpacks, battery check of beacon, transceiver check, etc.

Avalanche beacon and shovel training on Stubai glacier with colleagues from South Tirol and Trentino. (25.11.20019)
Safety training in Zürs. (photo: 02.12.2019)

What’s next?

The situation looks quite good for the coming period. A favourable avalanche situation will persist.

The stress-free pleasures of backcountry ski tours. Caution urged towards rocks near the surface. (photo: 01.12.2019)

Impressions from Axamer Lizum on 03.12.2019: Video: Simon Rainer




More and more ski areas have opened. The low temperatures are being used to make artificial snow. Axamer Lizum. (photo: 03.12.2019)

Isolated avalanche prone locations exist, particularly where there are small snowdrift accumulations at high altitude, increasingly near ridgelines in relatively shady terrain. In addition, glide-snow avalanches are still possible in isolated cases, which can grow to large size in the regions of the south where snowfall has been heaviest. The ironclad rule is still valid: avoid all zones below glide cracks.

On Monday, 9 December, the ZAMG Weather Service forecasts a small amount of snowfall in the furthermost western regions. Presumably, avalanche danger will then increase. For details – as usual – consult the Avalanche Bulletin on 8 December at 5:00 pm.