There was a fair it of rain on Monday night.
Yesterday morning Chiltern Railways services appeared to start well, until it became obvious from the Marylebone Arrivals Board that something was amiss.
The problem turned out to be water, lots of water, near Northolt Park & Sudbury Hill Harrow stations. I think there was also further flooding out at Haddenham in Oxfordshire.
For a time no trains ran yesterday (10th February 2009) between West Ruislip and London Marylebone. By nine o'clock (am) trains were able to run through North West London albeit very slowly, with flood water lapping away at the top of the rails.
It's all rather strange - this particular railway company was hardly affected by last week's snow, but surplus water brings altogether different problems.