Ok, I think I located the issue @rda2w you are seeing. I am guessing that you are using the latitude,longitude preference option (primarily for non USA countries that do not have a 5 digit zipcode) for TWC local weather rather than 5 digit USA zipcode.
When I used an incorrect latitude,longitude value (I reversed my lat,long), the error was produced that you are seeing. Check your latitude,longitude value in the SmartApp and if you desire, you can enter a 5 digit zipcode instead of lat,long since you are located in the USA… I also updated the Ambient Weather Station SmartApp to provide an example of lat,long.
My lat,log value is 39.7,-83.9 and when I entered this in the preference for local weather, it returned the accurate timezone by TWC API for local weather at this location, etc…
2:46:58 PM: info Main (#170) Section: Executing Local Weather Routines for: 39.7,-83.9 & Ambient Weather Station API's for: 'TimberRidge'
Hope this works for you!