The precipitation charts show the amount, type and probability of precipitation.
Precipitation amount is shown in mm (which corresponds to liter per square meter) for the respective time period (e.g. 1 hour). Total precipitation amount (blue bars) is the sum of shower (light blue bars) and frontal precipitation (not indicated separately).
Precipitation types are rain (no separate symbol), snow (*), and freezing rain (!). Hail is only displayed for special services. If Precipitation falls as snow, the height of the snow cover can be indicated separately - otherwise, multiply the amount of water by the factor 10 to obtain snow cover.
Precipitation probability is calculated from the predicted cloud conditions, the frequency of precipitation forecasts in the region and the frequency of precipitation in previous forecasts, and is shown in percent (%).
Cloud charts show the cloud development during the forecast period, from 0 to 14 kilometer altitude above sea level (km asl). Cloud density is shown in grey scale steps (see chart legend).
The average altitude of the surrounding area is plotted on the bottom of the chart. In the sample chart (right side), the selected place (Belalp) is on 1985 m asl, whereas the average altitude of the region is 1200 m. On same days (like on the night from Saturday to Sunday), cloud base (lower end of the clouds) may be below the altitude of the location selected. This can mean fog in the lower areas.
Under tropical conditions , the cloud altitude can reach 1 to 3 km more than indicated.
From the height, density and sequence of the clouds, you can interpret the type of weather expected. A typical cold front starts with low clouds, which build up over time. Thunderstorm weather is characterized by cloudless mornings and rapid cloud development during the day, with dense and high clouds in the afternoon, which may disappear again during the night.
After using to the cloud graph for some time, you will find it easy to understand the expected weather patterns.
Wind charts show the hourly wind speed and direction during the forecast period. Wind speed is shown in a curve (km/h) for maximum wind speed (wind gusts) during the previous indicated hour.
Wind direction is shown by wind barbs indicating the cardinal directions (N, S, E, W) from which the wind is blowing. A wind barb from the North indicates wind blowing from North to South.
For more information on wind speeds and definitions, see our Wind page.
|The barb begins with a feather and finishes in a point. The wind blows from the feather towards the point. The number of "feathers" (lines at the end of the barb) represent the speed.|