Halvarssons definitely works for me, I also got caught in the very same Belgian deluge and not a thing got through and talk about adaptable, with the three layers to suit virtually any type of weather. Really affordable as well
Another Klim fan here. By far the best jacket I've ever had. Laminated Goretex so it breathes, but you don't have problems when it rains (100% dry so far). It's kept me dry in extreme wet (Scotland, Wales) and cool in Spain/Portugal due to good vents, though it was unseasonably cool. It took me a long time to justify spending so much but it really is value for money when you stay dry and comfortable. Difficult brand to find though.
It's the Klim Latitude Bradders. It's a shell without any fleece or other insulation so you just wear layers under to suit the season. Can be used all year.