Here's the most recent imagery from @zoom_earth. The smoke line that leaves Marseille towards the south-east comes from the fire that started this morning at the north of the city, at the north of it. As the Mistral wind blows from north-west to south-east, the fire progresses towards the city very quickly, and the smoke has been passing over us for the last hours.

A screencast from Windy for the last 6 hours. We can see both Marseille & Narbonne fire panaches spreading over the sea on this one. Which means that the Tramontane must have started to blow in Narbonne. Not a good news. (Or it changed direction?)

A screencast from recent satellite imagery showing clouds and fire smoke over the Mediterranean.
A screencast from recent satellite imagery showing clouds and fire smoke over the Mediterranean.