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Raten (Oberaegeri), Switzerland

Latitude: 47° 8' 30'' N

Longitude: 8° 39' 50'' E

10 June 2016 0919 (Local Time)
Camera direction: towards NNE

Image P/S code: P.8.15

Image I.D.: 4787

C_L = 6, C_M = /, C_H = /

Stratus fractus silvagenitus
This time lapse covers 53 minutes in the mid-morning above a forested area in central Switzerland. Strong overnight radiational cooling and high moisture content from rain over the three previous days resulted in cooling and early morning formation of Stratus and fog.

The time lapse commences with the Stratus dissipating in some parts while elsewhere lifting and transforming into Cumulus fractus of dry weather. The clearance of the Stratus and fog has resulted in localized surface heating and the establishment of thermal currents. The high moisture content, enhanced by evaporation and evapotranspiration from the tree canopy, has resulted in the thermals cooling to reach saturation at a height just above the tree canopy.

This is an example of the new mother-cloud silvagenitus – in this case, Stratus fractus silvagenitus.
Links in the image description will highlight features on the image. Mouse over the features for more detail.
© Franz Feldmann
Raten (Oberaegeri), Switzerland
Latitude: 47° 8' 30'' N
Longitude: 8° 39' 50'' E
10 June 2016 0919 (Local Time)

Camera direction: towards NNE
C_L = 6, C_M = /, C_H = /
Image P/S code: P.8.15
Image I.D.: 4787
The sounding is from 135 km west-south-west. The 0000 UTC sounding had a 4 °C temperature inversion from the surface to 925 hPa. The 1200 UTC sounding, meanwhile, has a shallow, unstable layer surface to 949 hPa (lowest 55 m). It is conditionally unstable from 949 to 860 hPa, and dry and stable from 850 to 603 hPa.
© MeteoSwiss 2016
Accumulated precipitation (24 hours) only in the western hills of Jura, Switzerland, 100 km west of the location of the time lapse
© MeteoSwiss 2016
Stratus fractus silvagenitus and Altocumulus
There are special cases where clouds may form or grow as a consequence of certain, often localized, generating factors that are either natural or the result of human activity. One natural case is when clouds develop locally over forests due to increased humidity caused by evaporation and evapotranspiration from the tree canopy. In this photograph, we see wisps of Stratus cloud rising above the forest at 1 and 2. The irregular, ragged nature of the cloud defines the species as fractus, and as the cloud is forming above a forest, we may add the special cloud name silvagenitus. Thunderstorms and rain in the area over the preceding hours had increased the relative humidity. Also visible in the image is a layer of Altocumulus stratiformis cloud.
Links in the image description will highlight features on the image. Mouse over the features for more detail.
© Petr Hykš
Ždánice, Czech Republic
Latitude: 49° 4' 5'' N
Longitude: 17° 1' 24'' E
27 July 2015 1738 (Local Time)

Camera direction: towards W
C_L = 6, C_M = 3, C_H = 0
Image P/S code: S.8.15
Image I.D.: 5593

Stratus fractus silvagenitus

Stratus fractus silvagenitus and Altocumulus