The maps "New Snow" are published daily from November 1st to June 30th and updated several times a day. The new snow maps are available for the three time ranges 24 hours, 48 hours and 72 hours. The selected time range can seamlessly transition from the past to the future and can be set to any time period between 3 days in the past and 3 days in the future (feature only available on the application WhiteRisk for now). Time ranges that extend over more than 24 hours are calculated from the sum of the 24 hours snow depths.
The 24 hours retrospective of the current day is first adjusted and improved at 8.30 am with measurement data of the current day. Until this time, the new snow maps of the current day are based on pure model data. At 10.30 a.m., 4.30 p.m. and 10.30 p.m. the new snow analysis is updated again with the measured data that have been delivered in the meantime.
The new snow maps are based on calculations by the operational snow-hydrological service of the SLF (OSHD), using precipitation date and the operational weather models of MeteoSwiss as well as the assimilation of snow measurement data from around 440 automatic weather stations and observer data. The calculations take into account various processes such as the settlement of new snow or the melting of new snow in the event of significant warming or rain. It also takes into account when the snow falls on snow-free and still warm ground and therefore melts again.
The new snow maps are based on snow modelling by the operational snow hydrological service of the SLF (OSHD), using input data from the operational weather forecast models of MeteoSwiss and the assimilation of snow depth data from around 440 automatic weather stations and observers. In addition, the 24-hourly new snow measurements at the manual measuring fields of SLF and MeteoSwiss are assimilated. The calculations take into account various processes such as the settlement of new snow or the melting of new snow in the event of significant warming or rain. It also takes into account when the snow falls on impermeable and still warm ground and therefore melts again.
The data are modelled for the whole of Switzerland with a resolution of approx. 250x250 m and then smoothed for the presentation.
A time history of the data from individual measuring stations can be viewed on the measured value map.