As experienced spotters will know, low clouds can sometimes line up parallel to the wind to form cumulus radiatus, also known as cloud streets.
While it is not uncommon for convection currents to form such patterns, photos like this that clearly show the clouds rolled into strips are apparently rare. It was taken by a Japanese coast guard aircraft off the north-eastern coast of Hokkaido.
As an added treat, you can watch a video of the cloud streets shot through the aircraft window.
Our Japanese is a little rusty but we are reliably informed that the narration says the clouds floated just over the sea surface, stood 300 metres tall and stretched for more than 100 kilometers.
Thanks to Craig Butcher (member 9808) for telling us about it.