During wintertime this map is published daily at 9.30 am. It shows the amount of fresh snow that has fallen during the preceding 3 days. The depicted value in each case is the sum of the previous 3 days’ 1-day new snow depths (see 1-day new snow map). In view of the continuous settling process, this sum is usually greater than the value that would be obtained by measuring the increase in depth once at the end of the period. The variables are measured by hand, so that the recorded values are fairly reliable. They are not always verified, however, so errors cannot be ruled out.
Most of the measuring sites are situated in intermediate altitude zones, between 1000 and 2000 m. If the fresh snow at the site is moist, or if rain is falling, the amounts of snow lying at higher altitudes will be greater.