Well I looked at lots of forecasts on lots of sites, and calculated a high probability of lots of rain ...
A lot of the free (or relatively cheap) websites which "do" forecasting, use the same US computer model, which is freely available, but has a rather coarse physical resolution (iirc 75km). This probably doesn't matter as much in a large country, but I suspect that the UK websites probably interpolate the data to get a finer resolution, which isn't going to be very accurate. The US model is also reckoned to be very poor beyond 7 days (although that's not really an issue with tonight!). The main reason that people use it, is that it's cost free, whereas most of the other people who could provide useful information for the UK, cost money (probably quite significant amounts of money).
I think Simon does pay to get the more detailed forecast information from the Met Office.
The current forecasts seem to have moved the slight rain forecast for today, to slightly earlier than it was being forecast yesterday, and a bit less of it (not that it was forecasting much more than drizzle anyway). I'm going to have to make a quick decision on how wet the roads are going to be, and whether it'll be worth putting RaceBlades on
Red, but my current thinking is that the roads will probably be dry, or very near to it, so I'm not expecting to need to bother with any more fettling.
... (Given the lightning damage to Southern Railways last night I might not have made it to Victoria in any case.)
I believe that's all mostly cleared up now. I think there was some problems early on, probably primarily through rolling stock not being in the right places, but I would guess by this evening it'll have been cleared up entirely.
I plonked all of the lights and batteries on charge before I left for work, with seven chargers plugged in!