Avalanche forecast in 3 languages: the phrase catalog

Avalanche warnings in the Alps

The Alps are an extraordinarily complex mountain range, unique on earth. In no other mountain range of the world do so many countries and cultures meet in such a compressed area. Eight nations with five highly contrasting languages share a space which is only one third the area of Italy (surface area of the Alps: 200,000 km²). And the various avalanche warning services in this area are just as multifarious as the Alps themselves.

Depiction of warning zones of the various avalanche warning services in the European Alps on European Avalanche Warning Services website  (www.avalanches.org).

Throughout the wide-spanning arc of the Alps, more than 30 different avalanche warning services prepare and publish a regional avalanche forecast for the public. The differences are startling: some of the warning services publish descriptions of the current situation (bulletin); others prognosticate avalanche danger for the near future (forecast); some warning services publish their reports and warnings every day, others at longer intervals. The time of publication of avalanche bulletins and forecasts varies from country to country. The largest disparities, or those causing the greatest concern, are those which appear on the websites of the respective warning services: the products look completely different, present their data in different ways with different formats and depictions and frequently are available only in the language of that given country.

The products of the various avalanche warning services often have widely disparate appearances and are usually only in the language of that one country. Above left, Veneto (Italy), above right Vanoise (France)

The Euregio Avalanche Report

The intensive collaboration of the avalanche warning services of the European region Tirol-South Tirol-Trentino and the compilation and publication of a joint avalanche forecast is something brand new, never before seen in the world. The Avalanche Report spans a bridge over national borders, over different languages, presents a unified look in several languages. Both a Trentino backcountry skier in Tirol and a Tirolean snowshoe hiker in Trentino will find a familiar report whenever they consult it. All the relevant current information on avalanche dangers can be gleaned at a regular time of day in his/her own language. And so that even the British and Slovenes in South Tirol can be given assistance, the report is also presented in English.

The new Avalanche Report in Euregio South Tirol-Tirol-Trentino: in several languages and cross-border coverage.

For static websites whose contents do not change (or change only seldom), a three-language depiction can be brought about with relatively little effort. Texts are translated once and remain the same for an indeterminate period of time.

It gets complicated, however, when it is a matter of the avalanche forecast, which is our main product. This is published each and every day at 5:00 pm in all three languages simultaneously. When the situation changes, an update subsequently follows at 8:00 in the morning. In case of extraordinary situations, an update is possible at any time of day. The texts of danger description and snowpack analysis change daily. In addition, the number of avalanche-endangered regions and thus, the texts which need to be translated, vary greatly (see Blog).

Eine professionelle Übersetzung der Lawinenvorhersage in zwei weitere Sprachen wäre somit mit enormem Aufwand und nicht zuletzt finanziellen Kosten verbunden - wäre da nicht der Satzkatalog!

The phrase catalog

The phrase catalog is a fully automated translation system developed specially for avalanche forecasts by the WSL Institute for Snow and Avalanche Research SLF in Davos.

It is based on a complex catalog of pre-defined sets of words which together build a vast variety of sentences and then are translated into all required languages. When an avalanche forecast is generated, the descriptions of avalanche danger and snowpack analysis are not written freely, but combined like a linguistic puzzle consisting of pre-defined pieces, so that it is immediately available in all three languages. The point of departure, i.e. original language, can be German, as is the case in Tirol and South Tirol, or also Italian, as is the case in South Tirol and Trentino.

Through the permutations of linguistic building blocks, vast contents stand at the ready and can be combined to describe each and every situation precisely.

The phrase catalog enables warning services to generate a translation of avalanche danger assessment and snowpack analysis into German, Italian, English and French automatically.

Since Germanic and Romance languages have quite different grammar, there are built-in limitations to automated translations. The result is generally shorter and simpler sentences which might in some cases sound unusual or repetitive. What is more important, however, is that the information is presented clearly and understandably in all the required languages.

With the help of the phrase catalog and the automated translations connected to it, the avalanche forecaster is directly and immediately present for all readers in all requisite languages in the published report.

Conclusion

The new Avalanche Report in Euregio South Tirol-Tirol-Trentino is no longer written freely by a translator, but rather, assembled automatically by a complex catalog of highly varied sentences which produce countless combinations and which at the push of a button can then appear in German, Italian and English.

Using the phrase catalog demands a big transformation of the avalanche forecasters who stand on the front line. Yet the advantage of the Avalanche Report - that up-do-date versions are always available in three languages - have higher priority.

  

This new system was made possible by the successful collaboration with our colleagues at the avalanche warning service at the WSL Institute for Snow and Avalanche Research SLF in Davos. We extend a deep vote of thanks for their cooperative assistance.

Weak old-snow layers demand caution. Gliding snow increasing.

Current situation

Weak layers in the old snow are currently the main problem for winter sports in Tirol’s mountains.

In East Tirol, separate from the Main Alpine Ridge, the old-snow problem is striking. Due to the shallow snowpack at the end of January, markedly weak layers formed near ground level consisting of faceted snow crystals and depth hoar, and were covered over by fresh snow last week. Between about 1600  m and 2600 m, these weak layers can, in places, be triggered by minimum additional loading, e.g. the weight of one sole skier. Most critical are W-N-E aspects. Due to the depth of the fresh snow, avalanches which fracture in the weak old snow fundment can grow to large size.

In addition, in far-reaching parts of Tirol on south-facing slopes (SE-S-SW) in a narrow altitude band of about 2300-2600 m, we see a weak layer of faceted crystals which developed around a melt-freeze crust in mid-January. In the last few days we have had numerous reports of settling noises and avalanches (see blog of 04.02.) connected to this layer. Prior to the most recent snowfall, this weak layer was quite superficial. In regions where snowfall was heavier, and on slopes which were starkly wind-loaded, the characteristics of the slab, from the point of view of skiers, are less favourable: fractures can propagate far more easily and avalanches can grow to greater magnitude. In East Tirol, this weak layer is part of the weak old-snow fundament.

Snow profile from the borderline Sextner Dolomites from 05.02.2019. SW; 2090m; 34 degrees. In central East Tirol and Dolomites, the fresh snow from last week covers a weak snowpack base. The profile shows depth hoar near the ground and the melt-freeze crust above that, with faceted crystals from mid-January. (©Lukas Rastner; Sarah Graf).

Snow profile in eastern Verwall Massif (Madlein). SW; 2550m; 43 degrees. Weak layers for potential slab avalanches are found near the upper surface above and below melt-freeze crusts. The snowpack layering beneath that is very stable. (©LWD Tirol).

In the snow profile depicted above, a stability test provoked a fracture (ECTP2) above the melt-freeze crust from 16 January. (photo: 06.02.2019).

The weak layer from mid-January led to numerous naturally triggered avalanches during the precipitation last weekend on south-facing slopes between about 2300 and 2600 m. (photo: 06.02.2019).

In the Zillertal Alps, Tux Alps and central Stubai Alps a fracture down to more deeply embedded layers of the old snow is still conceivable. Namely, on very steep, shady slopes between about 2300 and 2600 m. It is likely that only large additional loading will trigger one. The avalanche prone locations occur relatively seldom.

Old-snow problems are always treacherous. They lurk inside the snowpack, making avalanche prone locations unrecognizable for backcountry skiers and freeriders. When aspects and altitude zones are pointed out in the Avalanche Bulletin in this connection, we recommend a defensive route selection. Large, steep slopes should be avoided. 

The current warm temperatures, which are expected to persist through Sunday (see “Outlook”), will also bring about heightened gliding-snow activity. Due to the depth of the snowpack all the way down to low altitudes, glide-snow avalanches can attain great magnitude. The rule of thumb is: circumvent all zones below glide-snow cracks. 

Winters with lots of snow mean high gliding-snow activity. (photo: 06.02.2019).

Positive:

In far reaching parts of North Tirol, quite good backcountry touring conditions currently prevail. On south-facing slopes the snow has been strongly affected by the sunshine. On north-facing slopes, however, the loose fresh snow which fell during the cold front on Sunday, 03.02, can be enjoyed to the hilt. The wide-ranging snowdrift accumulations of last week have bonded well with the old snowpack and are unlikely to trigger. In isolated cases, trigger-sensitive snowdrift accumulations are found on shady slopes adjacent to ridgelines at high and high alpine altitudes, but they are generally small.

Fabulous powder snow on north-facing slopes, as here near the Zittauer Refuge in the Zillertal Alps.  (photo: 05.02.2019).

Surface hoar formed on the snowpack surface during the clear, cold nights. Whereas the sun has more or less decimated this on south-facing slopes, on shady slopes they constitute a weak layer for future snowfall. (photo: 05.02.2019).

  

In northern East Tirol (above, Venediger Massif) winds were strong in recent days and heavily impacted the snowpack surface. (photo: 06.02.2019).

Outlook

In the early morning hours of Friday, 08.02, a weak cold front will reach us in whose wake a few centimeters of fresh snow are expected in the northern regions above 800-1200 m. Winds will increase somewhat, thus, fresh snowdrift accumulations will be generated, particularly on shady ridgeline slopes. They will be small but easy to trigger, in some places deposited on top of light-fluffy snow or surface hoar. The avalanche prone locations will be easy to recognize.

On Friday, snowdrift accumulations will form particularly near ridgelines, most of them small but easily triggered.

Between Friday, 08.02 and Sunday, 10.02, sunshine and cloudiness will alternate. It will remain relatively mild for this juncture of the season. This intermediate warm period will have a positive effect of stabilizing the snowpack on south-facing slopes: the trigger sensitivity of the weak layer in North Tirol will decrease somewhat due to the effects of warmth and solar radiation. On the other hand, gliding snow activity on steep, grass-covered slopes will increase.

Gliding snow activity will be heightened over the next few days. Gartalm, eastern Tux Alps. (photo: 06.02.2019).

On Sunday night, a weather perturbance is anticipated which will bring precipitation, lower temperatures and strong-velocity NW winds. New snowdrift accumulations will be generated, avalanche danger will increase.

The old-snow problem will persist, particularly in East Tirol.

Through Sunday, 10.02.2019, it will remain unseasonably mild. A weather perturbance will follow, bringing lower temperatures and precipitation. (©meteoblue).

On Sunday night, some fresh snow is expected throughout Tirol.

Numerous avalanches in Tirol exhort caution, esp. in central + southern East Tirol

Numerous avalanches

During the last few days, numerous avalanches in Tirol have been registered. These were naturally triggered releases in the regions where snowfall has been heaviest, on the one hand; on the other, avalanches triggered by skiers and freeriders. To date, no one has suffered injuries.

In the interim, the phase of naturally triggered slab avalanches has more or less passed. And precisely for that reason, it is important to remind skiers and freeriders that the situation is still quite dangerous, particularly in the central and southern parts of East Tirol, where a striking old-snow problem threatens.

Avalanche danger map in Avalanche Bulletin of 05.02.2019: high danger for skiers in furthermost south

Due to the old-snow problem, slab avalanches can fracture across wide areas and grow to dangerously large size around all those engaged in winter sports. Near the Bösen Weibeles in East Tirol, one group of skiers had incredible luck. By a hair, they missed being swept along. Good luck and perfectly functioning rescue action of group members also led to a fortunate conclusion in Hochfügen in the Tux Alps when someone was completely buried in snow masses.

Photo of an avalanche below the Pfaffenbichl in Hochfügen, made available to us be the Alpine Police: north, about 2300 m, 35-40 degrees. The slab released when two persons were traversing the slope. A person who was totally buried in snow masses was found and rescued. (photo: 02.02.2019)

Avalanche triggered on Hohe Mut South, in rear Ötztal (photo: 02.02.2019)

Slab avalanches on Vennspitze in the Zillertal Alps. North, about 35 degrees, about 2300 m, no one buried.  (photo: 04.02.2019)

In North Tirol, additional avalanches released today, 04.02.2019, in the uppermost snowdrift layers. The avalanches were generally small-to-medium sized, frequently triggering on south-facing slopes at 2100-2600 m. This can probably be attributed to the superficial weak layer of faceted crystals beneath a melt-freeze crust described in the last blog entry.

Furthermore, numerous reports of shooting cracks and settling noises have been reported over the last few days, in North Tirol their frequency is decreasing.

Shooting cracks near Salfeins in the northern Stubai Alps (photo: 02.02.2019)

The loosely-bonded upper snow layer frequently proves to be treacherous, since there was no wind in many places as the last phase of snowfall came to an end. Thus, the previously accumulated snowdrifts couldn’t be recognized (as easily).

Loosely-bonded snowpack surface (starting today, more loose-snow avalanches) atop a harshly wind-impacted snowpack surface near Schartenkogel in the Tux Alps  (photo: 04.02.2019)

For a better grasp of the critical situation prevailing in far-reaching parts of East Tirol, here is a...

Short review

The forecasts of ZAMG Weather Service were perfect once again. The southern part of East Tirol got most of the precipitation. Porzehütte station at 1935 m won the prize, with about 150 mm of precipitation.

Heavy snowfall in southern East Tirol

Southern East Tirol in winter garb: view of Lienz  (photo: 03.02.2019)

A decisive factor apart from fresh snow: fluctuating temperatures, plus storm-strength winds from varying directions.

Naturally triggered avalanches started to trigger rather quickly after precipitation set in. This was primarily due to the poor snowpack layering. Strong winds and rising temperatures during the snowfall also reinforced the dangerous situation.

Wide-area avalanches were frequent in southern East Tirol.  (photo: 02.02.2019)

Wide-area avalanches were frequent in southern East Tirol.  (photo: 04.02.2019)

A similar picture: Schleinitz near the Lienz Basin (photo: 04.02.2019)

When winds shifted to northerly, the next climax of avalanche activity was reached, namely, in the afternoon on 02.02.2019 and during the night.

What remains of this naturally triggered avalanche activity are the glide-snow avalanches on grass-covered slope. These are utterly unpredictable and will assuredly increase in the coming days as temperatures rise, particularly in North Tirol and East Tirol.

Much experience, much restraint called for in outlying terrain, especially in East Tirol

For backcountry skiing and freeriding tours, extensive experience in assessing avalanche risks on-site is called for...and a high degree of restraint, particularly in East Tirol. We exhort all skiers and freeriders to control their urges, restrain themselves! Caution is also urged due to possible remote triggerings in flattish terrain.

In North Tirol, the focus should be placed first and foremost on the recently generated snowdrift accumulations. Avalanche prone locations are found increasingly in terrain adjacent to ridgelines in all aspects, but also on very steep to extremely steep south-facing slopes at 2100-2600 m.