Reflection on sky (Taivaanvahti, 11.10.2017)

[Timo Kuhmonen]

This one is first time I see this type of observation, looks cool I have not seen it real time myself.
http://www.taivaanvahti.fi/observations/show/67443

Comments mention in the observation, that it may be light reflection in the river surface, what is "projected" to cloudy sky (Aurajoki, city of Turku & Finland). In Youtube samples the phenomenon is pretty much in same place at sky, when the clouds are passing by...