An unattended, unpowered aircraft wouldn't jump its chocks in anything less than severe gale
Many years ago at BEA's Heathrow base I watched a BEA Trident jump its chocks ( I think they may have only been on the nose) and it proceed slowly backwards between the main base hangers.
We calledf or assistance and some engineering types arrived. They jumped out of their Transit van only to see it too being blown backwards.
The Trident appeared to be in a very sheltered location, nose to the wind.
It certainly was not a severe gale blowing but must have been the effect of the wind coming off the adjacent Hangers.