I have had some success with this.
First, setup a Javascript Debug config and configure it like so: Imgur: The magic of the Internet
Also map dist/index.html to http://localhost:4200/index.html
Then, run ember serve, make sure the jetbrains chrome extension is installed, and then you can run your debug config. When you run it, it will open it url in chrome, and you can set breakpoints in your Jetbrains IDE.
I have had mixed success with this, it works, but the sourcemapping seems to be wonky.
Please let me know if you find an improvement in the configuration.