Between Saturday and Monday up to 200cms of fresh snow fell in the southern Alps, while milder air in northern areas meant that fell as heavy rain, said MeteoSuisse.
The situation raised the avalanche risk to the maximum 5 in many parts of the snow-covered Swiss Alps – though that was lowered to 4 on Tuesday morning – while flooding and landslides have hit lower altitude regions.
The Gotthard road tunnel was closed on Monday evening in both directions after a mudslide covered 50m of the tarmac, trapping one vehicle and damaging both lanes, Uri police said.
No one was injured but the road is currently closed indefinitely.
The road and railway to Zermatt remained inaccessible on Tuesday morning, as were roads to the ski villages of Zinal, St Luc, Saas-Fee, Leukerbad and Arolla, said the Touring Club Switzerland.
Further north, the road alongside Lake Brienz between Interlaken and Meiringen was closed, and in the east the roads between Brail and Zernez, and Lavin and Giarsun in the canton of Graubunden were blocked.
At Lommiswil in the canton of Solothurn a train derailed on Monday evening due to a landslide caused by heavy rain, police said. The line remains disrupted until further notice.
Solothurn police also received around 100 calls from members of the public, mostly concerning flooded buildings.
Many trains were disrupted in the cantons of Vaud and Valais, including the mountain train between Aigle and the ski resort of Leysin which was closed on Tuesday morning due to the risk of landslide, according to SBB. A bus replacement service is runnning.
Also affected in the canton of Vaud were the lines Villars-Bretaye, Le Sepey-Les Diablerets and Haut-de-Caux-Rochers-de-Naye and Les Avants-Montbovon.
The lines to Zermatt and Andermatt remained closed on Tuesday due to avalanche risk, as was the Gotthard panoramic route between Erstfeld and Biasca.
Rail disruption on Tuesday morning. Source: SBB
The precipitation ceased on Tuesday and the weather is forecast to be calmer in the coming days.