I'm having similar thoughts. Previous experience suggests that at these temperatures my sense of humour is rated for about 3 hours of heavy rain, assuming a minimum of hanging around (which is by no means a given on a Fridays ride). The forecast is currently for about 3 hours of light rain, and then pissing it down forever...
It seems that getting soaked in gritty skog on two consecutive days of racing at dePreston last weekend didn't even slightly appease the weather gods.
There also appear to be some train issues between Mordor Central and Wolverhampton, though I expect those to be resolved by this evening.
I'm going to keep an eye on things and make a decision later...