A low pressure system will be sitting over England and the North Sea for much of the week, and disturbances in the midlevels of the atmosphere will move around this low and across northern France. Since the pattern will be slow to change, the chance of rain will remain high for several days. While showers will be possible at any time of the day on Wednesday, Thursday, and Friday, the afternoons appear to be the favored times for the majority of showers. The amount of rain through this period could be between 1 and 2 inches (or 25 to 50 mm). As we get into Friday night and Saturday morning, the low pressure trough will begin to move east, taking most of the rain with it. I am putting a low chance of rain in the forecast for Saturday due to the uncertainty about how fast the trough will exit, and if there is rain into Saturday, it is more likely to be early in the day. I am confident that the rain will be completely gone by Saturday night, as high pressure will begin to build over France from the west. This will give a nice day on Sunday for the finish of the race. Right now, I'd put the chances of a dry race from start to finish at 80%.
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