14.01.2019 | 17:00h | News SLF
Avalanche danger is diminishing, isolated large-sized naturally triggered avalanches possible
Since the beginning of this period of precipitation on Saturday evening until Monday afternoon, there was 60 to 120 cm of fresh snow registered over widespread areas above aproximately 1500 m on the northern Alpine Ridge, in parts of the Valais, in northern Grisons and in the Lower Engadine, also greater amounts from place to place. On Monday in these regions, numerous naturally triggered avalanches were registered, some of them were of extremely large size.
The precipitation is slackening off and will come to an end on Monday night. Furthermore, during the course of the day on Tuesday the northerly winds will also slacken off. Thus, the avalanche danger levels can be expected to incrementally decrease. To start with, however, very large-sized to extremely-large sized naturally triggered avalanches will still be possible over widespread areas in isolated cases.
Second-highest danger level, ongoing
The SLF ranks avalanche danger for Tuesday, 15. January 2019 for practically the entire region of the Alps at danger level 4 (high). The conditions are very critical. Exposed transportation routes and free-standing buildings are at risk. The instructions of authorized safety authorities and local safety service organisations must be followed precisely and without delay. In all regions which are threatened, we urgently advise snow sports enthusiasts not to leave the secured and marked ski runs.
Extraordinary snow situation
The current situation is extraordinary with regard to the long-enduring rounds of new fallen snow, in the northeastern regions of the Swiss Alps above 1000 m more than anywhere else. In these regions, the sum of new snow depths which have been registered over the last two weeks is between 2 and 3 metres. Such conditions, that so much snow falls within 15 days, occur only every 20-50 years. As a result of the enduring snowfall, it is likely that some measurement stations register new maximum new snow sums by tomorrow morning, as regards the overall amounts covering 15 days.
The current snow depths in the northeastern regions of the Swiss Alps are approximately twice the normal amounts at this juncture of the season. In accordance with these snow depths, about a dozen longstanding measurement stations in these regions have recorded new snow-depth records for mid-January.
The next Avalanche Bulletin will be published on Tuesday, 15 January 2019, at 8:00 am.