The good news is that conditions should be improving through the weekend. The low pressure system will be tracking away on Friday, taking any chance of rain with it. Clouds will linger into Friday morning, but there should be at least a little sun by the afternoon which will bring temperatures up into the 50s.
There will be a stationary front across central France over the weekend, with high pressure over England. I expect that any rain will stay to the south of Belgium near that front, and the high pressure over England will have the greater influence on the weekend's weather. So my forecast for the weekend will be dry and partly cloudy, with highs in the upper 50s. However, there is some uncertainty about the positioning of the front, and if it ends up being farther north, I may need to add a chance of rain to the weekend with later forecast updates. Let's hope that doesn't happen.