Coming from Lyon (LYS) the Bordeaux controller advised about "light to moderate" reported turbulence south of the Pyrenees. Maintaining FL310 as higher levels were occupied, just north of ZAZ we had 355/95 kts winds.
Within about 3-5 seconds the wind dropped to absolute 0 and the IAS dropped by about 40 kts with the autothrottle figthing at max thrust settings. The OAT increased by about 7 degrees.
Recovering the aeroplane from about 12 degrees nose up pitch we were hit by a sudden 50 -65 kts headwind, bringing the IAS very close to VMO. At the same time we experienced gusting effects which forced up to 25 degrees bank in both directions......
We got an immediate descent to FL 270 and all was fine there.... beside the cabin, my dinner all over the cockpit, my coffee dripping from the roof.
Beside a thorough cleaning of the aeroplane from inside, the engineers were just excited to go through a complete "severe turbulence check"....
No, there was no warning, no, there were absolutely no clouds around....
And no, never experienced anything like this before