That's stunning! You'd think there was a wildfire nearby (not sure if that's a problem in the UK like it is here in the western US).
There were/are wildfires in Portugal that contributed - ie about a 1000 miles away!
We do have wildfires, but they weren't even seen as a serious threat until 2012 after
several bad ones in 2011. Britain mostly deforested itself and so there's not vast expanses of woodland (though there are many ancient woods) save for those created more recently for forestry industry. All large wooded areas are fairly intensely managed. Certainly, near London, there is very little.
Things like Epping Forest and the New Forest, and other former-Royal hunting forests (Sherwood, though that's mostly been changed again) are mixed - some wooded areas, but broken up. Grazing is a key role for much of the English countryside, and sheep (and ponies in this New Forest example
here) aren't want to leave anything above a fine tooth comb, so one has to work against them to make copses - fences and the like, until the saplings become big enough to not get eaten.
Is the storm dropping a bit of sand, or is it mostly staying in the air?
It didn't drop it - here at least - it didn't even rain. I think the particles were very fine anyway, so it would be hard to notice anything other than a big drop.
Storm Brian (the second extratropical cyclone of the UK/Ireland winter storm season that ex-Hurricane Orphelia has dominated) have given today several short sharp showers, windy throughout and cloud-cover changing repeatedly.
