With help from michoob over at XDA and an unknown programmer we have created a mortscript that uses Google Maps to get your phone's GPS location, convert that location into the U.S. zipcode you are in, and then adds that zipcode as the first location in your TF3D weather tab.
Also thanks to the creator of CommandWeatherConfig3 over at XDA (I don't remember the name right now)
This is working on my Sprint Diamond with the latest official rom on the HTC website. It should work on all other versions of TF3D (1st Gen).
You must have Google maps installed to Internal Storage\Program Files\GoogleMaps for this to work. Your GPS must be also be turned on in google maps for this to work. Lastly, under Settings > System > External GPS, COM4 must be selected as the port that program will use to obtain GPS data.
FOLLOW THESE INSTRUCTIONS TO GET MY LOCATION ADDED TO YOUR TF3D WEATHER TAB:
1)Install mortscript (cab is below) and reboot your Diamond.
2)Create the directory "Internal Storage\Program Files\CWC" on your Diamond
3)Unzip the contents of "CWC.zip" to the directory in step 2
4)Execute CmdWC3.exe and wait for it to finish
5)Reboot your Diamond
6)Go to your weather tab & remove all of the locations entered. Add this as the first city on your weather tab: My Location > My Loc (ZIP:10001). It wil be under "My Location" at the bottom of the list. Re-add the locations you previouly had in your TF3D weather tab.
7)Reboot your phone & insure that "My Loc (ZIP:10001)" is still the first location in your TF3D weather tab.
Unzip TF3D1MyLocWX.zip to anywhere on your Diamond's main memory
9)Run TF3D1MyLocWX.mscr
Any time you want to update your location-based weather run TF3D1MyLocWX.mscr
TF3D1MyLocWX.zip
CWC.zip
MortScript-4.2.zip