© Martin Gudd
Sponheim, Germany
Latitude: 49° 50' 50'' N
Longitude: 7° 43' 18'' E
15 May 2010 1638 (Local Time)
Camera direction: towards W
Image P/S code: P.7.14
Image I.D.: 5113
CL = 5, CM = /, CH = /
This image shows a grey layer of Stratocumulus cloud with a relatively uniform base that indicates the species stratiformis. It is sufficiently thick and opaque to mask the position of the Sun, which identifies the variety opacus. Interestingly, parts of the cloud base present an accentuated relief in the form of udders or inverted mounds, which is the supplementary feature mamma. They should not be confused with the wrinkled appearance that can appear with certain kinds of Altostratus opacus. Prior to the time of the image, Cumulus clouds were seen to rapidly spread out into this layer of Stratocumulus, to which we may therefore add the tag cumulogenitus. The nearby sounding shows a pronounced inversion, under which the cloud spread out.
Links in the image description will highlight features on the image. Mouse over the features for more detail.
The surface chart from about 9 hours after the photograph was taken shows low “Xena” with a pressure of 999 hPa centred over Denmark. A cold north-westerly airflow covers central Europe, with weak anticyclonic influence over France and western Germany.
The nearby sounding at Idar-Oberstein, Germany (WMO 10618) shows a deep layer of low-level moisture from 900 to 750 hPa, above which the layer is capped by a strong inversion.
The satellite image shows the situation at the time of the photo and some time before the photo was taken. Low clouds are seen over central Germany, indicating the cold north-westerly airflow. To the north-west, the low clouds are smaller, indicating the anticyclonic influence. To the north and to the south-east, high clouds show the location of two lows. Between these features, over the middle parts of Germany, a pronounced inversion developed.