The photo below posted today, titled, "Strange clouds" is an example of virga. Virga (also called fallstreaks) are wisps or streaks of rain or ice crystals precipitating out of a cloud, which evaporate before hitting the ground. Virga falling from high clouds made of ice crystals frequently angle back from the parent cloud, as seen in the photo below, "Sunset Virga". This happens because the winds at cloud level (where the jet stream can be) are usually higher than the winds closer to the surface. However, the photo "Wispy downward trend" shows virga falling from a cloud where the winds at cloud level and below are the same.
Sunset Virga
A nice display of virga at sunset.
Strange clouds
Photo taken in the Czech Replublic while on holday.
Wispy downward trend
This cloud almost looks like a tornado, but it was virga ... I think.