Ember cli very slow to start

I'm new to Ember.js and I'm trying to set up a basic app to work with my Rails API. So far I've only got one route and component, but it's taking an extremely long time to compile:

Livereload server on http://localhost:49153
Serving on http://localhost:4200/

Build successful - 118663ms.

Slowest Trees                                 | Total               
----------------------------------------------+---------------------
Babel                                         | 29584ms             
Babel                                         | 17291ms             
Babel                                         | 8697ms              
SourceMapConcat: Concat: Addon JS             | 7880ms              

Slowest Trees (cumulative)                    | Total (avg)         
----------------------------------------------+---------------------
Babel (12)                                    | 74194ms (6182 ms)   
SourceMapConcat: Concat: Addon JS (1)         | 7880ms       

What could be going on here? My app is using Ember 2.4.4, Ember Data 2.4.3, and jQuery 2.2.3. Once it finally starts up, everything is fairly normal in terms of speed. I really want to like Ember, but is this poor performance normal?

Thanks for any help or tips!