I'm not quite sure what 'black ice' is, but the most treacherous condition is when ice is covered by a new drizzle of snow on a relatively mild winter day. You can't even see where it's slippery or not. I've had a few tumbles over the years -- both on foot and bike (I've never owned a car), but thankfully nothing severe so far.
It's ice that is very thin but covers a large amount of surface area. On roads, you see the normally dark color of the tarmac through the ice cover, which is why it is so treacherous - you can't visually detect it.
There are usually stairs leading up to properties and if you step onto an ice-covered step and your feet suddenly slide uncontrollably, then aside from the horrible feeling of toppling over, that is when you're most likely to sustain a nasty injury so I totally understand where you're coming from, Thor. Sometimes you recover and then an instant later the same thing happens all over again in the danger spots. In those circumstances I always follow the nearest snow line and tread on the side where I can feel the crunch underfoot, if possible. But then again, don't we all?
I'm sitting at the desk with the blind drawn, but notice it seems a bit brighter outside than it should be for night time. I pull up the blind and outside it's . . . snowing.
A complete contrast to the abnormally high temperatures we've been experiencing for the time of year. But it's equally odd that we go so suddenly to what would be more normal weather for this time of year without experiencing a more gradual change in temperature gradient over several days.
It rained all day yesterday just outside London, I didn't go out. It's very overcast & cold & damp today, but sod it, I'm wrapping up going out for a good long walk, & visit a few charity shops now they've re-opened (I'm a bit of a charity shop addict).
The snow hasn't really settled, however, it is noticeably colder and the sky lighting generally feels a bit more Christmas-like. It's one of those personally subjective atmospheric connections to the season. Anyway, only 21 more days to go, though God only knows what the high street is going to resemble in these uncertain times.