The answer is Weather STAR: http://www.weather.com/aboutus/television/star.html
The C3-13 transponder on C-Band which carries Weather Channel to cable companies and DBS providers carries the embedded local info. TWC gives headends that carry TWC the WeatherSTAR decoder which decodes the info...
You can't FTA on a Phase 3 DTV dish. You need a Ku-Band dish like those of primestar. The satellites that FTA channels are broadcast are those with Linear Polarity (H-V) and not those of Circular Polarity (L-R, DTV and E* use this)