The first flake comes as an exhilarating surprise. It is not alone, that's definitely snow. A mother and her small daughter share the joy, pausing their walk to beam at the animated sky. The queue outside the bakery looks up and chatters excitably. The streets have a dusting like icing sugar. It's been a year since London saw anything like it.
The flakes fall larger and faster - proper Christmas card stuff. Families come out onto their doorsteps to watch, or gather on their balconies, or start togging up in coats and scarves and hats. The queue outside the coffee shop disperses to upload the scene to Insta. It's been a couple of years since London saw anything like it.
The air is swirling. It's what Londoners like to call a blizzard despite being nothing of the sort. The grass in the park is increasingly covered, not just with snow but also with people come to experience it. Toddlers stare in wonder at something they've never seen before. It could ultimately be the heaviest fall London's seen in years.
The snow has reached that special thickness where it scrunches underfoot. One boy's rolled enough to make the bottom of a snowman - his sister's working on the head. Even the trees are catching it now. What chance 'Stay At Home' when outside is such fun? Flip your camera to capture a winning face'n'flakes selfie. It's been a full hour now and London is agog.
The rate of snowfall looks to be easing. Watch your footing on the slushy pavement, it's starting to get slippery. People are cold and wet now and the novelty's wearing off - should've brought a warmer hat. It'll not be long before the magic fades, the grass is green again and the brief excitement but a memory. Watch the skies.