If you look at the satellite sequence at
Satellite: Europe ? yr.no and the dust spectral sequence at
EUMETSAT IPPS animation - Meteosat 0 degree Dust Western Europe (select the 24 frame option) you can see the bulk of the plume was created yesterday and seemed to stop around midnight, with a small 1-2 hour burst in the wee hours. Most of the "cloud" seems to have passed thru the North Sea, and is primarily resident (now) in the Netherlands/Benelux area. Must have significantly dispersed though, one would think.