Eidgenössisches Institut für Schnee- und Lawinenforschung Institut Fédéral pour l'Etude de la Neige et des Avalanches Istituto Federale per lo Studio della Neve e delle Valanghe Institut Federal per la Perscrutaziun da la Naiv e da las Lavinas

National avalanche bulletin no. 126 from Monday, 2 April 2007, 18:30 hours

Generally favourable avalanche situation

Current conditions On Monday it was generally sunny in the Swiss Alps. Midday temperatures at 2000 m were about plus 3 degrees in the west and plus 1 degree in the east. There was a light wind from various directions. Moderate southerly winds have given rise to some fresh, relatively small snow drift accumulations in recent days, especially adjacent to the ridge line. These have been prone to easy release. In addition, rather weak near-surface layers exist particularly on north facing slopes in some regions; these can fail especially if exposed to a large additional load. In the inneralpine regions in particular, the snowpack also has a weak base in many places, which can give rise to avalanches with large fracture depths.

Short-term development Tuesday morning will remain fairly sunny in the north. In the afternoon cloud will build up from the north. A little snow will subsequently fall above approximately 1500 m. On the southern flank of the Alps it will be generally sunny. Midday temperatures at 2000 m will be about minus 1 degree. The northerly winds will freshen to moderate strength in the afternoon. In areas adjacent to the ridge line, the wind will once again transport larger quantities of snow.

Avalanche danger forecast for Tuesday Northern Alpine ridge; Valais; northern and excluding Lower and Lower Val Moesa: Moderate avalanche danger (level 2) Avalanche prone locations are to be found, in particular, on west to north to east facing steep slopes. These locations are above approximately 2400 m in Lower Engadine and above approximately 2200 m elsewhere. Fairly old snow drift accumulations, but also small fresh ones being formed by the northerly wind especially in areas adjacent to the ridge line and pass areas, are to be treated with special caution because they can be released easily in some places. Snow sport participants are to continue engaging in activities one at a time, with spacing between individuals, on very steep north facing slopes in particular. Careful route selection is important. Northern prealps; remaining northern flank of the Western Swiss Alps; central Ticino; Lower Val Moesa and Lower Val Calanca: Low avalanche danger (level 1) Isolated avalanche prone locations are to be found on extremely steep north facing slopes in particular. In these places, avalanches can still be triggered by high additional loads. On very steep sunny slopes below approximately 2600 m in Valais and on the southern flank of the Alps in particular, small wet snow slides and small avalanches can occur during the day.

Trend for Wednesday and Thursday Some snow will fall in the period until midday on Wednesday, especially in the north. Thursday will be largely sunny as milder weather returns. The avalanche danger will temporarily increase a little in some regions.

Additional information: ‘Fax-on-demand’ (CHF 1.49/min.) Regional avalanche bulletins (CHF 1.49/min.) Feedback information: 0900 59 2020 List of fax aids SLF 0900 59 20 31 Central Switzerland Free telephone: 0800 800 187 0900 59 2025 Snow Depths Map (in case of major change) 0900 59 20 32 Lower Valais / VD Free fax: 0800 800 188 0900 59 2026 New Snow Map daily 0900 59 20 33 Upper Valais Internet: http://www.slf.ch 0900 162 338 Alpine Weather Report MeteoSwiss 0900 59 20 34 North and Central Grisons Email: [email protected] (CHF 2./min.) 0900 59 20 35 South Grisons WAP: wap.slf.ch Weather Information in collaboration 0900 59 20 36 Bernese Oberland Teletext: Page 782 (SF DRS) with MeteoSwiss 0900 59 20 37 Eastern Part of the Northern Slope of the Alps