My mother in law bought me the Canari Tour jacket in a pale lilac color, and I love it. It's lightweight but it stops the wind and it's water resistent, the sleeves zip off (and you can also just unzip them at the armpits for ventilation), it has a nice big zipped pocket at the rear and two front zipped pockets, it's nice and sleek so it doesn't catch the wind, and the whole thing folds up into itself if you don't need it. It actually has some straps so you can wear it around your waist, but it's also small enough to fit inside the exterior bungee on my Camelbak. I have worn it in damp 50 degree weather and been plenty warm, and then partially unzipped the front zipper and the sleeves, and I was also fine at 70 degrees.

It's a discontinued style but they do turn up on eBay now and then. (Hey, here is one now.) I sort of wish mine were a brighter color for visibility, but the lilac sure is pretty. Mine is a medium. I usually buy tops in large, but I don't think I would want this any bigger.