I did one years ago in very light conditions - they shortened course to finish at Bembridge Ledge and we and the other 1800 finished in the dark at about 2300.
It was a magical experience coming round the back surrounded by navigation lights, but if its the same this year do take loads of beer - we ran out
select "Weather" then "Weather Area Forecasts Worldwide - select area from Map"
Select "UK" then "Charts - 5 Days" The isobar charts are then revealed. Alternatively after "Charts - 5 Days" select "Alternative Site" and you can then watch the weather charts changing (which is where I got the file from)
Hope that is clear enough /forums/images/graemlins/laugh.gif