Legend of the graphs about the
"SNOW AND WEATHER CONDITIONS OF THE 7 LAST DAYS"


This section of the Snow and Avalanche Bulletin is composed by three images, one for each of the main mountain massifs of the Aosta Valley, in which the trend of some snow and weather parameters of the last 7 days is represented. A brief description of each graph is reported below.

The mountain massifs considered are

For each mountain massif the following parameters are represented (starting from the top of each image):

WEATHER CONDITIONS
For the morning and afternoon, the weather conditions icons, published in the weather forecast of the Centro funzionale regionale, are indicated. While for the night the data is not available.

FREEZING LEVEL
The freezing level is indicated for the morning, afternoon and night. The freezing level for each mountain massif has been calculated starting from the values of the automatic weather stations located in the relatives macrozones those into which the Valle d'Aosta Region is divided for the snow and avalanche bulletin. Since the original data is hourly, to simplify it is considered:
  • for the morning: the minimum value since 6.00 am to 12.00 am
  • for the afternoon: the maximum value since 12.00 am to 6.00 pm
  • for the night: the mean value since 6.00 pm to 6.00 am.


WIND AT 3000 m
In order to be able to indicate the wind data at 3000m, we chose to use the 700hPa data coming from the forecast model Cosmoi2, because they are more representative of the conditions in the free atmosphere. Given the extension of the massifs, since there are multiple values, it was decided to represent the 90th percentile of the intensity data and the wind direction obtained from a weighted average with the intensity cube. The runs considered by Cosmo-2i are the following
  • for the morning: runs 06, 09
  • for the afternoon: runs 12,15
  • for the night: runs 18, 21, 24, 27.


AVALANCHE DANGER LEVELS
The icons identifying the avalanche danger levels extracted from the corresponding snow and avalanche bulletin are shown. For each massif two or more microzones of the snow and avalanche bulletin are considered; whereas only one data can be published, we chose to report the highest danger levels.

SNOW DEPTH
The snow depth data at 2000m and 2500m are represented, considering the median value of the snow dephs modeled by the S3M model relative to these altitudes and considering a range of ± 200m. The results of the S3M model can be consulted on the Snow Maps page.

NEW SNOW
In a similar way to that one indicated for the snow depth, data at 2000m and 2500m relating to the new snow of the last 24 hours are processed from the S3M model, whose maps are found on the Snow Maps page





The raw data used, with the exception of those relating to the avalanche danger level, are owned by the Meteorological Office of the Centro funzionale regionale of the Regione Autonoma Valle d’Aosta. Wind data are processed from the Cosmo-2i model, acquired by the CINECA computer center, and made available by the Meteorological Office of the Centro funzionale of the Regione Autonoma Valle d’Aosta as part of the institutional activities related to the Civil Protection System



The creation and publication of these graphs is possible thanks to the Project “RISK-GEST”, of the Piano Integrato tematico (PITEM) “RISK - Resilienza, Informazione, Sensibilizzazione e Comunicazione ai cittadini”, funded by Programma di Cooperazione transfrontaliera Italia/Francia “ALCOTRA” 2014/20 (FESR).