What is the weight of this jacket, is it...
What is the weight of this jacket, is it light enough to carry in a jersey pocket?
In case you were still waiting to find the weight of this jacket: I looked on the Castelli site, and could not find the weights, and it seems this one has been discontinued. You may have to actually contact them if you're still interested.
I can tell you that the Gore ALP-2.0 jacket is very packable...I carry this in my hydration pack, always, just in case! It is super light weight, water-proof (Gore-Tex), windproof, has a removable hood, and back apron that can be dropped down during rainy rides, or snapped back into place and out of view. It is just a shell, and in colder rides, a base layer and or winter jersey can been worn underneath. I use this on top of my winter jackets if it's blustery/rain.