I am using FSXWX, it's free, and it does the job for me (using P3d 2.3). The only thing, make sure you have simconnect in the old FSX folder..this program however connects to SUIPC from P3D and correctly transfers/updates regularly the weather. It's a very small app, takes up 0 resources, I love it!
http://www.plane-pics.de/fsxwx/home.htm