Hi Mike!
(My first post to this forum.)
I was looking for suggestions on how to add a city to WW and found the FAQ link:
That helped me immensely, thank you! 
After adding my city, I thought to verify that Weather.com used the right one and confirmed it on a helpful site which summarizes a ton of weather station city codes that I thought you could add to that FAQ article (if you see its usefulness):
http://edg3.co.uk/snippets/weather-location-codes/
There’s a search box on that page to search by location name and returns the code you need to add to WW.
The “catch”, I suppose, is that Weather.com carries info for that particular location. If it doesn’t, then WW would not download any data.
Thanks again for an awesome app!!
Greg (in Montreal)