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Savonlinna, Finland

Latitude: 61° 52' 32'' N

Longitude: 28° 51' 56'' E

21 July 2008 0835 (Local Time)
Camera direction: towards SW

Image P/S code: S.8.2

Image I.D.: 5497

C_L = 6, C_M = /, C_H = /

Stratus fractus with praecipitatio
This image shows the general grey colour associated with Stratus. Sometimes Stratus shows the ragged or irregular edges of the species fractus, as seen in this image. Fractus can be a transition stage in the formation of Stratus, which in this case was merging with a higher-based Stratus nebulosus, seen as a lighter shade of grey in the distance. The opaque nature of the cloud defines the variety opacus, while the supplementary feature praecipitatio can be seen as drizzle, which was reducing visibility to an estimated 3 km.
Links in the image description will highlight features on the image. Mouse over the features for more detail.
© Jarmo Koistinen
Savonlinna, Finland
Latitude: 61° 52' 32'' N
Longitude: 28° 51' 56'' E
21 July 2008 0835 (Local Time)

Camera direction: towards SW
C_L = 6, C_M = /, C_H = /
Image P/S code: S.8.2
Image I.D.: 5497
Low pressure of 998 hPa was located over central Finland. An associated warm front occlusion had passed over the image location the previous night. At the time of the cloud image, the occlusion's rain band was hook-shaped (back-bending) and wrapped around the quasi-stationary low centre, extending into southern Finland (further than the DWD chart suggests). The cloud image was taken inside the occlusion hook, which is a region of light winds, much low cloud and intermittent precipitation.
© Deutscher Wetterdienst
The sounding was taken close to the time of the cloud image and about 180 km to the west-north-west. It was inside the hook-shaped rain band of the occlusion and shows the stable, humid nature of the lower troposphere, with a weak wind structure near the low centre.
© University of Wyoming
The radar image shows the location and viewing direction (red arrow) of the cloud image; the location of the sounding (black arrow); and the approximate location of the low centre (white L). The nearest radar, 150 km (location KO) to the south-west, was unable to detect the low-level drizzle due to beam overshooting and the small droplet size of the drizzle. The large precipitating area to the south-west is the tip of the rain band of the occlusion hook.
© Finnish Meteorological Institute
The wide cloud band of the occluded front is present in the western part of this Fengyun-1 image (channels 1, 2 and 4) from about 12 minutes after the radar and cloud images. The location of the cloud image is approximately in the middle of the satellite image, in the wide area of lower clouds represented as a yellowish colour.
© Finnish Meteorological Institute
Stratus fractus of dry weather
Stratus is generally a grey layer of cloud with a fairly uniform base, but sometimes it appears in the form of ragged patches. In this photograph, the Stratus is dark grey and has the appearance of irregular, ragged (fractured) shreds of cloud (seen at 1, 2 and 3); the outlines were changing quickly and ceaselessly. These characteristics define the species fractus. Furthermore, because the cloud was not caused by precipitation, it is Stratus fractus of good weather. It should not be confused with Cumulus fractus, which is whiter and denser. Stratus fractus also shows less vertical development, as it forms mainly due to turbulence, rather than thermal convection. Also visible in the image are a layer of Altocumulus stratiformis and patches of Cirrocumulus.
Links in the image description will highlight features on the image. Mouse over the features for more detail.
© Michael Bruhn
Aspendale Gardens, Victoria, Australia
Latitude: 38° 1' 29'' S
Longitude: 145° 6' 48'' E
17 December 2010 1908 (Local Time)

Camera direction: towards WNW
C_L = 6, C_M = 3, C_H = 9
Image P/S code: P.8.2
Image I.D.: 5873

Stratus fractus with praecipitatio

Stratus fractus of dry weather