Information about the snow depth map (HS) + data ≥ 2000 m

The map is published every day at 10:00 a.m. and shows the depth of snow on the ground.

The map shows:

- the spatialized data obtained from the S3M model (Snow Multidata Mapping and Modeling). S3M uses a dynamic model that describes, in a simplified way, the snowpack evolution, through the snow observations (from automatic weather stations) and the MODIS satellite images (to distinguish snow-free areas from snow-covered ones). Also the data from  Modello1 AINEVA (MOD1) affect the result of the S3M model. In fact they are used by ARPA, together with the data coming from the automatic weather stations, for the weekly calculation of the Snow Water Equivalent (SWE). The SWE data is assimilated by the S3M model once a week. S3M runs, since 2009, on a national scale with a spatial resolution of 500x500 meters and time resolution of one hour. The map shows the simulation at 06.00 a.m. The model is operational at the Centro funzionale regionale as part of an agreement signed with the Fondazione Cima;

- manual observations from Modello1 AINEVA (MOD1) concerning the snowpack height (HS). Every morning, between 07:00 and 09:00 a.m., the observers measure the depth of snow on the ground. This map shows the observation fields located at an altitude equal to or greater than 2000 m a.s.l.. The measurement fields are fixed and located mainly in flat areas, possibly sheltered from the wind. The observations collected are punctual values: to define their position the best compromise was sought, but it must be remembered that, because of the extreme variability of the snow cover (due to wind, solar radiation, etc.), the measured data can differ significantly from other adjacent areas;

- data from the automatic weather stations (AWS) of the Centro funzionale regionale. In particular, for each station, the median value of the data is calculated every 30 min, between 06:00 and 09:00 am, in order to omit any obviously incorrect values. In the map only the stations that are located at an altitude equal to or greater than 2000 m are displayed. For more information on station data click here.

- manual observations from the Modello23 AINEVA (MOD23) concerning the snowpack height. These measurements can be carried out in fixed fields or in variable sites from time to time. The HS values accompany more complex information regarding the snowpack stratigraphy and stability. Since the observations are collected in places not easily accessible, although they are usually measured in the morning, they are shown on the map in the late morning or afternoon. These data, and the relative legend, are represented on the map only when available. In this map only the data at an altitude higher than 2000 m s.l.m. are displayed. The data collected manually (MOD23) are quite reliable, however the presence of any errors is not excluded.

- data measured by the snow poles (PALINE) concerning the snowpack height and positioned in crucial points of specific avalanche basins, monitored by the local avalanche commissions (CLV). These data are observed, often through binoculars, by the CLV members and therefore cannot have centimeter accuracy. Furthermore, it is possible that they are not representative of the entire area: in fact two snow poles, even if very close, may indicate two different snow heights, for example if one is located in an area notably subject to wind erosion and the other to wind deposit. The data, and the relative legend, are represented on the map only when available. This map only displays the snow poles located at an altitude higher than 2000 m a.s.l.

Corresponding map

NB - The map shows only the HS punctual data (AWS or MOD1/MOD23/PALINE) correctly collected and entered in the relative database. If missing, because they are not measured or not available, they are not displayed on the map, so the number of data may vary from day to day. The acronym N/A (Not Available) is used when computer problems, for which it is not possible to access the data (although present) of S3M, AWS and MOD1, occur.


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