"They can't drive in rain either. Or clear weather."
Haha! They must be from Missouri!

London is indeed rather ill prepared for snow, I remember a near total transport shutdown a few years ago due to only a few inches of snow.
Many of our trains are electric and these do not cope well with even modest snow, some use a live third rail to supply current to the train, these are especialy vulnerable.

I would assure those who have not seen it for themselves, that not just one, but dozens of snowflakes landed in central London.

Temperature at present is 2 degrees (centigrade) which is lower than average but not remarkable.
Last night it reached minus 4, again a little below average but not remarkable.

I have however resorted to wearing long underwear, which is not the norm.
Similar temperatures and a little more snow are expected.

This reminds me of a letter I recieved from my daughter in, I think, 2003. She was working as a short-term missionary in Lima, Peru. Lima sits in the world's second driest desert. All the water comes from rivers running from the Andes; never a trace of rain except in winter when some precip comes from a sea fog. On this one occasion, a thunderstorm formed and dropped an inch of rain. There were several drownings because the city had absolutely no way to handle storm run-off. Rain there is as rare as sand-storms in Antarctica.

we have electric trains here, including those with the third rail. they seem to have no trouble coping with snow.

To be strictly accurate I think that it might be ice rather than snow that causes railway problems, though of course snow may turn into ice.

I thought that all conductor rail electric railways were vulnerable to ice or snow, and that the technology was therefore little used in cold regions.

Oh, you wouldn't believe the really odd freaky ways snow and ice can disturb operations of basically anything. Some examples:

- Driving through powdery snow you get a huge cloud of very small and light snow particles. These will acumulate in the weirdest places on the undercarriage of a train, in ventilation slots and basically into any small crack where normal, plain water has no chance of ever coming. (The bodywork is designed so a drop of water will drip off the train, not dribble into cracks. Powdery snow flies everywhere you don't want it). If that doesn't disturb some mechanical operations or short circuit something electrical then the repeated melting and freezing caused by running in and out of (relatively warm) tunnels surely will enable water to short circuit something or ice buildup to disturb whatever mechanical.

- Frost on the cable will impair the connection between the train and cable.

- Any rubber-like material such as gaskets and seals will become brittle in the cold, so they won't work as intended (unless you use the right qualities).

- Any plastic will become brittle and may break (unless you use the proper materials)

- Huge temperature differences between the inside of the train and the outside means that most places in between you'll get plenty of condensation, as water or as frost. Think of how many that have trouble with their car doors when it's cold; a lot of those problems are due to condensation.

- Any door has a rubber gasket that can freeze so the door won't open (prevent with silicone grease!), and any door has a door lock that can freeze.

Robustifying against all and any places where powdery snow, water or condensation can cause trouble can be done, but it is typically fix-this-wait-for-next-problem kind of process. Not really difficult, but it takes time and effort.

Cars seem to have converged on a design that is pretty much robust against the effects of winter(with the exception of door locks for A LOT of car models), but a train has a lot more nooks, crannies and weird places for snow, frost and water to accumulate.

This is one of the joys of keyless entry; if the keyhole gets frozen you can still get in the car.

Maybe.Door can get frozen shut.And windows can get jammed when felt/rubber freezes,I now leave windows cracked open in freezing/wet/dew type weather,works very well.

Agreed,keyless is nice in wet/freeze!

A train caught fire earlier today at London Victoria station, fortunatly without any injuries.
Considerable disruption was caused though as the fire resulted in the evacuation of this busy London terminus in the morning rush hour.

The cause of the fire has not been announced, but I consider that snow ingress that melted is a possibility.
It is an electric train.

A red warning has now been issued which is fairly rare and a little more serious, though hardly TEOTWAWKI.

BBC NEWS